I disagree that Brent Key carries the same risk as Deion Sanders.
I think worst case scenario with Key is that he wins 5 or 6 games a year, has the kids playing hard, and leaves us in a decent place to upgrade coaches in three years.
Worst case for Deion is that he's completely out of his elements, wins a couple games a year, has a bunch of recruiting violations, and embarrasses the program on the national stage.
Of course he could also recruit gangbusters and make the playoffs in two years. Who knows.