Both Marka Ragnos and SF Malak are confirmed to be more powerful than Karness Muur by varyingly immense degrees. Muur is undisputably more powerful than Vector!Vader by a considerable degree.
KOTFE Arcann is vastly above the likes of Malgus; who by himself is already Vader tier due to feats and has better accolades than Vader too.
Add in back-up as strong as Dooku, Maul and even Bane are, with Thexan and Senya as added danger.
Sheev doesn't win, at all, in any sensible way.