Krayt isn't above Windu, but I have no problem with the other two. Windu would have to struggle to put Krayt down, (he's struggled with Bulq, Ventress, Grievous) all who Krayt is superior to in terms of force ability and dueling feats.
Satele has been bested by Malgus twice, and Kenobi has been sent flying by every darksider he's ever fought. In a contest of pure sabers it could go either way between Kun or Kenobi, but Kun outclasses him as a force user aside from Kenobi's TK.
I think the Sith take it with high difficulty and perhaps a casualty.