Kiffen is NOT a very good example of the point you TRY to make, he had a crappy year with the Raiders, one year at UT, and then got the USC job, HARDLY HC experience enough to learn the job.You are big on this prior HC experience... aren't you.
Frank had the same amount of coaching experience as Joe Paterno... Tom Osborne... Barry Switzer. All were promoted at their respective schools from coordinator to HC.
Not sure why anyone thinks a HC has to have been a HC somewhere else to say experience matters. Plenty of examples of HC's moving from one HC job to another and failing at their new job.
Kiffen comes immediately to mind...