Justin Fuente took over a Memphis program that was 3-21 in the previous 2 years and helped them ascend from the CUSA to the AAC (same conf as Cinci, UCF) and by Year 3 had them at 10 wins and 9 in Year 4. Everyone, myself included, thought he'd do exceptionally well at VaTech... he did not.
Mike Norvell took over for Fuente at Memphis and continued their success posting a 38-15 record including 2 division and 1 conference title in 4 years and 2 Top 25 finishes. Everyone thought he was an outstanding hire at Florida State... he is 8-12 so far after 2 years.
Tom Herman was 22-4 at Houston before taking the Texas job. He did not make it as he was fired with a 32-18 record and no losing seasons in 4 years.
Scott Frost was 19-7 in 2 years at UCF before taking the Nebraska job. So far he's 15-28 in 4 years but Nebraska, unlike a LOT of other schools, is showing patience and is giving him time.
Point is there are no sure things. There are plenty of examples of light-the-world-on-fire G5 coaches that have gone to a P5 program and have failed. And the impatience of these programs is only getting more and more thin. Look at Gus Malzahn... fired after 8 years, a 68-35 record (39-27 SEC) and 4 Top 25 finishes. Tom Herman had a good record at Texas. A lot of these programs (USC, FSU, Auburn, Florida, etc) demand immediate results and the pressure and toxic environment seemingly weighs on these G5 coaches.
And these schools basically have to hire either a coordinator or a G5 HC because no P5 coach will leave (and it seems a lot of good G5 coaches won't even leave) because of how insane these programs are. That's why guys like Matt Campbell, Luke Fickell, etc are staying put. Why would you leave a good thing to go to a swamp of toxicity?
I think Napier might be a good coach but IMO Florida will chew him up and spit him out just like they've done with every other coach... regardless of how successful they've been. We'd kill for Herman/Mullen's success in Hype's first 4 years. If he's not pulling in Top 10 classes AND winning 9/10 games by Year 3 out the door he'll go.