Mortis snapped people's necks with a flick of his wrist. He and Nox would utterly roflstomp instashot the Wrath. He's an unparalleled saber duelist in his own regard, but his real power comes from the fact that he's the Emperor's puppet.
And Jaesa was a wild, emotional little brat that an orobird could have turned to the dark side. Hell, her master was already corrupting her.
Now, Ashara is far better manipulated. To have a pawn that actually believes they're doing something for their own interest? That's far better than someone who takes your own philosophy, warps it, and then strives to eventually go beyond you, rather than work with you.
This debate always confuses me. Why would anyone possibly think a saber duelist could outmatch a sorcerer (not the advanced class, just going off lore here for the general term)? At the end of the day, a lightsaber isn't going to do much against something like