From many sources the fit is not great.  He is from South Dakota and not a good old southern boy.  If you think that does not matter in Alabama, think again.  Now, if he wins like Saban  did, they will build him a statue next to Saban and Bear, but if he falters again this year, the pitchforks will be out.  Having said that, he is on track to play for the SEC championship and a CFP playoff berth, so I do not think this is realistic
I agree it would be a massive downgrade for him, but getting out of Alabama may be appealing.