From experience, I respectfully submit that once a team gets in the wilderness, 3 years might be best case scenario. It's not that the school or the facilities or the fan base or any of that play into it. It's the fact that the hot players want to play at the hot schools, and it's hard to get the prestige back. You may be right and it'll happen quick, but the jury is out on Napier.
When Tennessee's coaching was obviously sucking, lots here were pining for Mullen, and he seemed to be "a good coach at a mediocre football school", and many wanted him in Knoxville. Crazy how one player (Dak Prescott) can make a coach seem like a genius. Analyze Josh Dobbs relationship with Butch Jones and you have almost the same thing.
If Napier can't put up the W's in the next three years, UF will have yet another coaching search. And NOBODY is immune to the wilderness. Take Alabama after Gene Stallings left. You had Mike Shula (bust), Mike Dubose (bust) Dennis Francione (bolted) and Mike Price (coached only the spring game). Those were good years for Tennessee. Bama might just suffer the same woes after Saban. That remains to be seen, and younger fans only see them as elite, and don't realize there are cycles. Some short and some long.