i always saw bison as a rush character. i barely turtle headstomps unless the other player is across the screen throwing fireballs at me. for every fireball i get at least one headstomp. on a regular basis that means i get to spam my headstomps about 10x times to be fair.
also, check out some tournament vids of bison, never turtles, but its not a bad tactic, its just a bad playing technique.
Ive yet to run into an offensive bison player other than using headstomp as offense. so tired of them just jumping up and following it up with that chop. When you try to move in they either teleport or b->f punch away.