There it is...
From what youve said i think you need to abuse her fireball more. Its really good at locking down the neutral a bit more, sheeva can straightup beat a number of characters in zoning and force them to come to you, or force them to do things that will get them telestomped. Ive not played any matchups that seems awful.Hot take: i dont think sheeva has any winning MU's. She has some that i would say go as far as being 7-3 in her opponents favour, like frost, but she has nothing that allows her to force her gameplan on the opponent. A 16f advancing mid is imo not answer to her range issues because every other character has faster ones. Even if you do get in, in most cases your opponent either needs to backdash or even just walk back to whiff punish pretty much anything you throw out.
her sweep/b3/throw blender would be better if the wakeup system wasn't a giant guessing game.
shes also very good at avoiding the mindgames other characters have with wakeups. After Db4mb you can legit just sit and wait and beat forward roll and u3/u2 with f1 whiff punish. Her multi hitting punches are good at checking wakeup buttons, stomp beats full delay wakeups, especially in the corner.
i cant see her having no winning matchups. I can also see why she has bad reach, she would be an actual potato if she could spank you miles away into staggers and endless 50/50s.
i will say i HATE the shao khan matchup, f34 is safe on sheeva. His d4 really dominates the matchup by itself WHY HAS IT GOT THAT MUCH PUSHBACK.