If a P5 job doesn't work out it still looks pretty good on the resume. Worst case you're back where you started at DC somewhere (but quite a bit richer) or HC at a smaller program, with the possibility of a 2nd chance. Non-P5 doesn't work out your options become more limited (and you're not as rich).I feel like he’d be better suited at a G5 school where he can put together a staff of up and comers like him (and a few experienced retreads) and work out the kinks of his HC style. Plus it won’t be as hard to win some games while said kinks are worked out.
Convincing good coaches to join him at a program that is in the gutter and run by a less than stellar athletic department and part of a dying conference might be tough to do. You have to be someone like BB who has tons of clout for that.
But maybe he’ll take to head coaching like a fish to water and be amazing!