This. Also, make it the H version.
Keep Rolling Buckler as it is.
Replace Cat Spike H with either Cat Spike M or Delta Kick M. Heck, even Toy Touch would be better.
In general, though, I think DPs should have invincibility until the ‘fall’ of the attack. Also, rather than make Tron and Haggar have useless assists, keep them invincible on start up but make their vulnerable state last a little bit longer.
I also wish we had some Grab assists like in MvC2. I had so many cheap as hell set-ups with Anakaris’ and Omega Red’s grab assist back then… I was honestly dreaming up similar shenanigans with Super Skrull before the game came out.