Did you not say he wasn't a good coach? GPA shows his ability to lead a bigger roster to do better than any coach before him. You are correlating it to the NFL.
The NFL is something he knows all about. He knows how front offices work and all the BS behind the scenes. He can definitely lead grown men. Because he hasn't coached in the league doesn't mean he can't. He has shown great leadership ability and I have no reason to believe it wouldn't transition to the NFL.