Sean doesn’t counter anyone. Like, he doesn’t counter Ryu at all. Ryu can do whatever he wants, and can still win. He can play defensively and just react to Sean’s limited bs, he can play offensively and take advantage of the fact that Sean has no good way to get anyone away from him without super but has real trouble building meter, or he can do a mix of both, etc.
Ok, the axe kick beats a shoryu if timed perfectly, but that’s still a problem. Sure, you can time it perfectly as a meaty, but too bad the move has such bad startup that if you use it as a meaty it’s super easy to parry, and also too bad that if you use it outside of meatiness, it can be beaten by anything with any speed. The roll can get you out of the corner once, at which point the opponent will not believe he was retarded enough to let that happen and won’t let it happen again. His dragon punch beats very few things if not ex, and even if it is ex, it still loses cleanly to throws and well-timed meaty attacks. Let me repeat that: his EX DRAGON PUNCH loses to THROWS. Not a good thing.
The tackle is his only special that gets any respect, but don’t use it to actually tackle. It’s just one part of a tick, really. Like, yeah, it’s true that if Ken does a standing fierce immediately before you land the tackle, that the tackle will win, but that will never happen ever, so there’s no use in really considering it. Yeah, you can use the roll for more (also limited) mindgames, but it’s not as “good” as the tackle.
Sean is limited to semi-decent pokes and roll/tackle throw games, and without meter he doesn’t have anything that’ll scare anyone.