Here's a great read about coaches beating teams with winning records. This is an old article (2014), but I think it'd still be valid today. I couldn't find any more recent stats...
"Did you know that of the 128 FBS head coaches, only 14—or 11 percent—have a career winning record against Top 25 teams?
Not only do 89 percent of the top level of college coaches have a losing record against ranked opponents, but 51—or 40 percent of the field—have never won a single game against a Top 25 team."
https://bleacherreport.com/articles/2137102-top-college-football-coaches-who-excel-and-struggle-against-top-25-teams
Rhule is a perfect fit for college. He relates well, can develop talent and build a team. It's easier to coach a guy looking to earn millions vs coaching a guy making millions....IMHO, he made a miscue that I hope he and new learned from. He was a brand new NFL HC and he got Joe Brady (for all intensive purposes) was very raw at the NFL level. Coupled with the complete crap show that was Carolina. It was an uphill battle. It was much easier for Rhule to field a competent college team when you can bring in 15-20 guys per class vs the NFL with 7 or less.....Quicker in college to get a lot of bodies and make a change. I think he'd do well. Bring Chadwell as OC