I do agree that Fous/Catchings and Mag/Keba might be more ideal pairings in the frontcourt. But Fous does not fit well into what most are expecting to be a 4.5 out scheme. He's also a lot more ball dominant offensively, which is bad news when we have at least 4-5 guys who'd be better off with the ball in their hands.
Fous will get much better matchups coming off the bench and that way he won't gum up our primary offense in the post. I do think KY may stagger minutes to get Catchings/Fous on the floor together, but I don't think it'll be both as starters.