I tried finding Power 5 new hire coaches for the past 5 years with no luck, but I found this, which, in a way, is going to support my thesis. In 2019, these were Head Coaches hired for the Power 5 conferences. At the time, these were sure-fire hires, soon to be the savior of the football programs in dire straights of becoming obsolete!!
Here are the coaches, how they were rated by the superior people of knowledge, which school, current status
1) Ryan Day, A-, tOSU, playing for championships
2) Neal Brown, A-, WVA, on the hot seat
3) Scott Satterfield, B-, Louisville, on the hot seat
4) Matt Wells, B-, Texas Tech, FIRED
5) Les Miles, B-, Kansas, FIRED due to past descressions at LSU...
6) Geoff Collins, C+, Georgia Tech, FIRED
7) Mike Locksley, C+, Maryland, Good hire
8) Manny Diaz, C, Miami, FIRED
9) Mel Tucker, C-, Colorado, No longer there (Maybe fired at MSU)
10) Chris Klieman, C-, Kansas State, Solid hire
11) Mack Brown, D+, UNC, Solid hire
On this list, 5 have been fired, 2 are on the hot seat, 1 Good hire, and 2 Solid hires. By the end of the year, probably 6 or 55% will no longer be with that school, 1 is still a toss-up, 1 is playing for championships, and 2 is on the doorstep of playing for conference championships. ONLY 1, or 9% of the coaches is considered a GREAT hire, 2, or 18% are playing for conference championships, and 1, or 9% is doing good enough to keep his job.
These coaches had either HC jobs in the past( lower divisions, lower conferences, P5 conference) or were coordinators. None of the above were position coaches only prior to being hired. This shows that no matter what you believe about experience, knowledge, or equivalent conferences or divisions, it is still a crap shoot. I also find it amusing that the bottom 2 in the grades are 2 of the successful coaches, goes to show that the talking heads are rarely right.
If anyone really believes there is a surefire hire out there, you are dreaming. I have hired many people, and in the long run, I found it best to bring them on board for 14 days (paid), at the end of those 14 days a determination would be made by both the applicant and myself if they stuck around. By the end of day 10, they start to show their colors and general attitude in life. I could teach people the landscape construction industry; (NO grass cutting), how to install patios, walls, fireplaces, and outdoor kitchens, build arbors, install lighting, and plant plants, but the one thing I could not teach is character, by then you either have it or you don't. The employees were the face of my company at all times, if they lack character and people skills I could not leave them alone with my customers. More people quit or were let go than those that I kept, maybe 1 out of 3 were kept on staff.
TA has the chance to see what type of character his staff is now and at the end of the season can let go of the weak links. The list above shows that about 36 % of the coaches are still viable 3 years later. This tells me that you better like the character and belief system of your coach long before you trust their potential. NOTHING is for sure, about one in three will make it, those are bad odds.