You're talking about Saturday casuals right? Because literally I did Makoto 3C, figured out that was low profiling shit, I can just 2A it.
But I guarantee that has never worked for Slayer, Potemkin, Testament, Tager, Bang, Arakune, Hakumen, Cielo, neutral, spacing, understanding the game beyond a level of hit buttons.
And more often than not I end up hating the game afterward, making me look like a real asshole (and me hating myself because of that), and saying "fuck it" and giving up has made most of that avoidable.
The only time I can really think where I actually figured out a matchup was in Wonderful World. Neva's annoying but has plenty of startup on a lot of her moves, so rather than playing from your maximum range, just be in her ass and make her suffer for it. And I attribute that more to Greats than anything I really did.
PS, that wasn't figured out in training mode.