The other underlying theory behind Mai anchor, I think, is to have scary characters preceding her. Put people in front of her who do a lot of damage for no meter, preferably ones who are both difficult to attack and defend regardless of how much meter they have.
To illustrate this theory, my current team is Clark/EX Kyo/Mai. The order might seem out of whack by conventional KOF logic, but here's the method to my madness:
Clark is first because he does a LOT of damage WITH meter, but he also does a serviceable amount of damage without meter (BnB into backbreaker), and more importantly, he is also the most mentally aggravating (IMO) of my three characters to fight. He has a 1-frame punish with hcf+D to defend against sloppy jump-ins. He has stupid loop-play shenanigans with hcf+B against opponents who freeze up or poke predictably. He has easy safe-jumps, a stupid good jump jab, a good jump D, a decent reaching punish with charge b,f+A that leads to resets into MORE stupid throw shenanigans. His only significant limitation is his attack range, which IMO is another good reason to put him earlier rather than later. If he dies early, I don't have to fight a zoning anchor with him, but with Kyo and Mai who are either better equipped to get in, or in Mai's case, better equipped to stay out. He's there to get in there, mess with the opponent, get them into a Clark-fighting mode, and do as much damage as he can for no meter before he dies. He's a much better experimental character than Mai because he can be either orthodox or random as fuck. He fucks with people. Plays stupid head games. Makes them mad.
EX Kyo is second because he's more orthodox than Clark, with a lot of the same damage input and a slightly better time against zoners. He can't experiment (in the Joseph Mengele sense) as well as Clark can, so he should come in when I'm (ideally) already up a bit. He corners people easily and thus gives me a lot of tactical room to think about whether or not I need meter to kill somebody ("Do I need that mid-screen DC or super to finish him off...or will he just die from corner mixup/pressure when he wakes up?". In 90% of player matchup cases, he will probably kill a 2nd character before he dies (if he doesn't win the match for me outright), which gives him a long enough lifespan to refund most of the meter he'll spend for Mai's sake.
Mai comes last because she NEEDS that meter just to stay afloat, and because IMO she is a good counter to most CONSERVATIVE anchor play. You can still beat her most easily by rushing her down smartly (if only to make her spend her meter to get away), but you have to do so with a lot more caution if she has NeoMAX. And if you get too careful against my anchor Mai, that's my cue to go kinda nuts, throwing safely spaced Kacho Sens to force you to get the fuck in my face and stop those goddamn fans...but CAREFULLY. Because I probably have NeoMAX. You can't do anything rash, and that makes it a LOT easier to play chicken with somebody creeping up on me rather than charging at me. Anything that makes my opponent move slower is to my advantage.
This of course all hinges on whether or not Mai has meter for NeoMAX stocked when she comes in. While it's a lot harder to hold it down if she doesn't, I believe the rest of my team is equipped to either live long enough to grant her that meter, or (even better) win without her even having to play. Her success is largely contingent on how well EX Kyo and Clark do. I'm totally okay with this.
That said, I'm not married to anchor Mai. Depending on the player/matchup, I might put her 2nd and EX Kyo 3rd. But if my opponent has a team that's 2/3-3/3 fireball characters, you better believe I'm putting Mai last. Fighting Ash without that NeoMAX is fun like cancer. Every time Mai's NeoMAX blows up an EX Sonic Boom or blocked Flash Kick, an angel gets its wings.