We now move on to the master of spam and Hachi's equal in power, Sensei.
Against most COs, the main Sensei strategy is going to be spamming COP while pursuing a Direct build centered around Recons, Tanks, and Copters. Whenever you hover around the unit limit, switch gears to SCOP for Mech firepower. Your powers are there to wear down the opponent and are also self-feeding, so most matches will boil down to a brief war of attrition before your real army busts through. Rear-spawning units can be combined for funds, making Sensei a poor man's economy CO as well.
Don't neglect Sensei's transport advantage. Often that one extra movement from T-Copters is enough to get to the map's center a turn or two before your opponent, and also to get to nice forward bases earlier in general.
The bulk of your unit count comes from your cities, so placing priority on capturing them is a must. Normally a CO can depend on units all coming from a particular direction while attacking your bases and defending theirs, but as Sensei you will divide their attention without dividing your real army (the one you paid for). Any time you must choose between capturing a city or base you must do some threat assessment: if the area is basically free of enemies, such as during the capture phase, you'll need bases to do any expanding. If there is fighting in the area, cities will give you many units for free, probably by the time you finish capturing. Sooner or later you must capture both since you have a real army to attend to and need to plug up your opponent's production.
Sensei probably has the easiest match-up against Grit. Grit has to wall off Artillery with the same units you're constantly spamming, so it doesn't take all that long to wear him down. While your mass of Infantry constantly annihilates this wall, some flanking Copters can go in and tear apart the Artillery. Tanks can also go through the holes, of course. As usual, if Grit attempts to answer you with anything but Indirects feel free to educate him.
This match-up is even easier than Grit, mainly due to the fact that Javier is ranked higher only because he can beat Grit. Technically speaking he is actually much worse without towers. Since Javier0T is basically bland against you with stats never going higher than 110/110 (against anything you'll be hitting him with), any strategy centered on Directs will take him apart fairly quickly.
Against Javier1T, even without a tower yourself you're basically fighting Von Bolt with the missile substituted for more firepower and defense. This firepower is not high enough to decimate your forces, and the defense isn't exactly impregnable. Approach like J0T, but make sure you're properly walling off your Tanks and Copters when they finish attacking.
For Javier2T, you're fighting Kanbei without weaknesses. Here you want to step your powers up to SCOP after the first COP, otherwise you probably won't wear down his units enough. As long as the match has both of you even with towers, this shouldn't pose too much of a challenge. Do not allow him to capture any of your towers or you're pretty much done. Even if you can out-produce him, the J2T SCOP is now his COP in an emergency, and his SCOP is invincible at full health (and pretty damn close if not). The kill ratio will be largely in his favor as such, and until you get that tower back it's an uphill battle. If he uses this advantage to get the fourth tower, you're screwed.
(Hachi is the only CO who really stands a chance against Javier in a six tower match, so I won't be mentioning J3T here or in further entries.)
As usual the biggest problem Lash will pose for you is the moderate defense she receives, and even that usually amounts to equal or less than what some COs can achieve on COP. To put it in perspective, after the default boost she basically has 130 defense on forests in addition to the normal two stars. Kanbei and Javier1T can manage that on COP. She also has very little firepower to speak of, so you can safely approach her like a slightly more annoying Javier.
His only two viable strategies are playing a weak Jess or a strong Grit with less range. Either way, Jake can't bring any significant firepower to bear against you, and isn't helped by its situational nature. Approach more or less like Lash without the defense.
If Sasha went with a COP strategy, your SCOP might be a bit slow getting out. Fortunately, you don't need SCOP to beat her and a Sasha player who knows what they're doing usually won't try to use Market Crash in any case. Copter Command is more than sufficient even with Sasha's attempts at teching up. She'll have more Tanks and Copters than you, but you have far more units to soak up the damage and weaken them. If the Tanks get out of hand you can just bank on your SCOP Mechs to shut them down. You have to think a bit, but it's not a challenge.
VS Luck COs
Plenty of potential for firepower, but against a numerically superior foe what you really need is defense in high proportions; something these three COs lack. The luck COs will punch holes in your army now and then, but they can't resist all the units you'll be throwing at them. Follow the overview, absorb the damage, and murder them.
He can get stuff to the front quicker and potentially meet you with more units. This does not solve Adder's problem with your sheer numbers, and once you whittle down his front line any concentration of units toward the front will give way either to a retreat or a lack of a fighting force.
Koal is pretty much Adder+. He has the same problem as far as overcoming your unit count (i.e. he can't), and his firepower doesn't make this much better. He's all about offense, and in a game where each unit can only shoot one other unit per turn, that doesn't help much against numerical superiority.
Andy's healing will allow him to resist your attempts at wearing him down with Infantry. Unlike him, you have better transports that can reach the center long before he does so that you can disgorge said Infantry on his front doorstep while another group grabs what you skipped. Ramp up production of Tanks and Copters, upgrade to SCOP, and just wail on him.
After you've spammed COP a few times for a wall, Grimm folds pretty easily to a combination of SCOP and teching up. He can hurt you pretty badly with his powers, but as I've said before you can't beat numerical superiority without some of your own or some high defense; neither of which are things Grimm is known for.
Treat Max like Grimm without the defense weakness. He'll take more punishment from your units, but he folds to the same strategy.
Jess is a slightly different breed of animal from the last two, but falls to about the same strategy. She incorporates some movement bonuses, but like many others she suffers from a lack of defense versus Sensei.
Sonja seems to have that defense I was talking about earlier; the kind needed to hold up against numerical superiority. There are two problems in your favor. The first is that Copter Command hits about twice as often as Counter Break. The second is that you don't have to attack Sonja when she uses Counter Break, and so she still has to try and attack all of your units. It also doesn't make her immune to superior-unit match-ups, so your Tanks and Copters will still be able to attack weaker units and take minimal damage, and use your mass of Infantry to wall off and protect against Sonja's own units next turn.
Drake -and indeed all of the mass damage COs- isn't a huge threat to your economy since your COP and SCOP units won't stay on their cities long enough to get hit by a mass damage strike. The free damage he deals lessens the gains on your CO bar, but considering your COP is only two stars it won't make a big difference. He's a pain in the ass if he catches you post-power since you'll have a bunch of 7HP Infantry that aren't gaining you any stars, and as usual the rain makes it hard to take advantage of his own post-power weakness. Otherwise this should pose no problems.
Like Andy, Hawke is equipped to deal with Infantry attrition, if not to quite the same degree. The moderate firepower combined with the healing can make him even more of a pain than Drake, and getting repeatedly hammered by it holds the danger of him breaking one of your forward centers (map permitting). Proper city hopping should let you reclaim any losses quickly, and from there it's just a matter of slow build-up until you can crush one of his expansions. Remember, as long as you're taking cities you're getting more units on each COP, which makes things much easier.
The biggest factor in your favor here is Hawke's colossal power bar. You can easily get off two or three COPs yourself before you have to deal with Hawke's SCOP, so you'll have plenty of units to keep soaking up damage once that hits.
This can be more troublesome than Hawke since Olaf is basically a firepower CO who wrecks your economy. Fortunately like all mass damage COs -and all COs in general- he can't hurt you with SCOP before you do your super expansion. Then, he still has to deal with at least two Copter Command uses before he gets Winter Fury, and has to try and catch you post-power with it to reduce your numbers. If you're managing your powers effectively, this won't happen.
VS Von Bolt
Ol' Vonny isn't a huge threat to you unless he catches you post-power, and even then it only amounts to an annoyance at best. The nice thing about Sensei's super spam is that you can just reinforce the mass of units Von Bolt freezes, defeating the purpose of his SCOP as a delay tactic. This is especially hurtful to him on a multi-front map since your own powers reinforce every front while his only freezes one, and like the previous COs you'll get several uses out of Copter Command before you ever have to deal with it.
This is an important pattern to remember: anything powerful enough to hurt you in post-power weakness takes so long to charge up that you'll already have too many units for them to kill.
This is another match-up that won't trouble you much provided you approach it correctly. Your normal spam tactic can get annihilated by the missiles unless you're exceptionally good at spreading out. An easier and arguably better tactic is to bank on your own SCOP and just wait her out. Sensei can beat Rachel on a day-to-day basis with that super expansion, so Rachel has to use her missiles. When she does, summon your free Mechs and bounce back. Lather, rinse, repeat. The unit count from super expansion should be enough on its own to keep Rachel from cutting through and hurting your ability to bounce back too much unless the map is very small.
Out of all the mass damage COs this is probably your easiest match-up. Kindle only focuses on damaging her opponent's funding base, but Sensei is the one CO in the game that doesn't rely on it. She'll mess up your captures, but she's no different from her fellows in that regard. It seems like she'd have to revert to a firepower-based SCOP strategy, but even against other COs she doesn't get much firepower that way, and against Sensei's super expansion she's even more disadvantaged.
Ealge is the only non-Tag in the game who can attack two of your units with one of his in the same turn, which gives him a better concentration of units toward the front. This is not enough units to match your superior numbers, though, and the awkward balance of his forces means that Eagle has nothing to fall back on once you penetrate and destroy his front line. Super expansion will give you the money needed for this strike, and spam will soak up damage from his units.
Sami's Mechs are stronger than yours, she spams them from the get-go, and she has super capturing. On her SCOP she also accomplishes a poor man's super expansion, and she likes to use Copters in place of vehicles.
You have a numerically superior force of similar composition to Sami's, and your Copters can one-shot hers. You also don't pay for most of your footsoldiers, and you'll primarily attack hers with the Tanks you're actually buying. Sami's SCOP might snag a property now and then, but often it will be to recapture lost properties rather than take yours.
This is going to be similar to Javier2T, except Kanbei's unit count will be a little lower. In contrast to your super expansion, Kanbei's expansion is a bit stalled at first. Once again you may be thinking that the defense I was talking about earlier applies here, but Javier3T is actually the only CO that has enough of it to take on Sensei. Kanbei suffers a similar problem to Sonja here since you won't be stupid enough to attack him when Samurai Spirit hits. It sounds like this should give him an advantage in numbers since you don't attack at all, but you'll have hit Copter Command at least twice before Kanbei hits SCOP the first time. This creates an insurmountable unit count advantage, typically a 10-15 unit lead. Though Kanbei can bog down these units with Samurai Spirit, he'll never be able to close the gap, and Sensei has plenty of time between its uses to kill Kanbei's units.
Colin will always out-tech and out-fund you. He cannot, however, out-number you. Even if he reaches full production from all bases, Colin can't match the numbers you turn out from your cities. The biggest threat here will be Md Tanks backed up by the occasional Bomber. Colin spams Gold Rush as often as you spam Copter Command, so this isn't difficult for him to do. You have to rely on Copters to take down the Md Tanks, otherwise you'll just have to whittle down their health. Fortunately this means Colin will be producing AAs, and do so prodigiously since your Tanks will be killing them. Wasting his time like this combined with your spam will allow you the necessary leeway to advance.
Sensei is an interesting opponent for himself. Barring force ranks, this is the only time you'll fight someone who can expand as fast as you do. This match will quickly devolve into a shit-fight in the center which will result in early COPs jump-starting expansion. The rest of the game will be spent with obscenely huge armies duking it out in the center until someone blinks.
This is the toughest match-up in the game since you and Hachi are about evenly matched. You both use spam, and while you expand faster Hachi techs up faster. Expect to have a combination of Black Bombs and mixed tank spam used to take your units apart. Spamming SCOP is necessary against Hachi; Infantry aren't going to cut it. You'll be working with slightly fewer units than you're used to with Sensei, but those units will be able to deal with the tanks being thrown at you. You'll be relying on Copters as with Colin to take on the heavier tanks, with Mechs acting as cannon fodder to destroy low-end units, dent high-end units, and feed your power bar. Your Tanks will serve the same purpose as the Mechs for the most part.
Map-permitting, abuse Sensei's super-expansion to the fullest. Your T-Copters can still reach the center long before Hachi can, and securing a foothold there will make the difference in getting your numbers up enough to deal with Hachi's tech-spam.
As far as using SCOP instead of COP, Hachi's own tactics work in your favor somewhat. To get his massive tech boost, Hachi likes to use Recons and lower on a day-to-day basis. If he didn't do this he'd just be a souped-up Colin, though it is by no means an easy fight in either case. Because Hachi usually stays low-tech at first, it gives you less reason to need Copter Command even if you weren't banking on Airborne Assault.
The reason Sensei is ranked so high is primarily a result of his super expansion combined with spam not having a good clear-cut counter. As I've said a thousand times in this post, Sensei's basic strategy comes down to rushing to the center, stonewalling, back-tracking, spamming, and attacking in that order. You can't get at his real force until it's already attacking you, sometimes not even then. His Copters can one-shot other Copters, reducing his Tank-Copter-AA triangle to a Tank-Copter line. His Tanks counter AAs, his Copters counter Tanks, and they also counter Copters. It's a huge money-saver that lets him be all offense all the time, and combined with the fact that opponents have to cut through his free units to get at his real ones there just aren't many good ways to beat him.