re: Jalen went from a "low IQ" Qb (Bama) to a Prolific Passer (OU) to an near MVP (NFL)

You make an excellent point. Sark and Kiffin are excellent QB developers, but not the greatest HC's out there (very good but not great). Lincoln Riley appears to be the best QB coach out there, but he's trying to be a HC, and the jury's still out.
If USC eventually cuts him loose, and I was the HC of an elite college football program, I'd give him the checkbook, and tell him to fill it in, then I'd sign it!