Bet he'll be a very good head coach at some point, remember his age and the positions he went to...they weren't small tasks, and he was young in coaching terms
I don't know if he'll ever get another head coaching opportunity to be honest. He fucked up an NFL gig by picking a fight with Al Davis and getting fired...walked out on Tennessee after not accomplishing much and headed to USC where he took a team pre-season ranked #1 and drove them into the ground.
Dude just can't coach the other coaches, which is essentially what a head coach does. But he knows offense and can excel on the one side of the ball he knows...we shall see I suppose.