Cassies is tricky I'll give you that so is Kotals because their hurtbox stays behind their hitbox so they beat you you out before your outside jump range you can def react to Dvorahs as she pushes her hurtbox in with her hitbox so you whiff punish her with one of your normals where your hurtbox is away from your box (damn I'm confusing myself
) usually everybody's D4 does the job if you don't feel confident of using a standing normal
Look at this way you see the start up frames being 11 frames so that's all your counting but if your 2-3 hits away in distance you have a lot of frames to react to as you count the active frames the start up of the next part of the string and the active frames of the next part of the string and so on depending on the distance and how much the opponent is willing to commit
Also it doesn't have to be reaction if your in s comfortable space to bait you can freely throw out fast recovering pokes and normals out randomly to catch an opponent advancing their string on a read and what that is also doing is giving your opponent a reason to attempt their advancing strings to whiff punish your pokes so your manipulating them to take the bait
Footsies is not just reaction it's also reads, how else do you think they are whiff punishing 4f moves in games like SF4 consistently