Klieman took over a program that was good and made it better, Bohl is in a conference that is mediocre to bad and can recruit his type of players from the local environment. Erntz would be walking into a meat grinder of a conference that shows no mercy. Bielema knows the success formula and is able to recruit from his past proven success in the B1G, I think Fickell is going to have it rough even though he has previous B1G experience. SEC & B1G football is a different animal than all the other conferences.
Erntz is a capable coach and does extremely well in his environment, but to make that big of a jump with no previous experience in a major conference would be tough. Leipold has worked under several major conference champions as an assistant and DeBoer coached at Fresno prior to his successful jump to the PAC 12. I watch almost every NDSU game and love their style of offense and defense, I would love for Rhule to imitate a lot of it, it works for their program. I think Erntz needs to stairstep himself into a Power 5 program. Not sure he could rebound from a NW flop. Not only that, but he walks on water right now, not sure he wants to give that up.