I don't see why both trainers have to be from FFVII. Tifa is a good choice, I'll admit (since basically every other FF female is a DID/magic user/thief type character) but Cloud is just plain stupid. What the smurf is a freaky brain-damaged super soldier doing as a trainer? You need another fistfighter. Sabin, Duncan or Yang is the obvious choice for the role, since they're martial artists. Even Wakka is a candidate; he's the only sports coach ever to appear in an FF game.

As for fat people? One of Leblanc's cronies in X-2 was fat, I think his name was Ormi. Josef (the guy who Borghen kills in FFII) sort of looks fat as well.