I think the reality of the situation is that there is no formula.
Is it an FCS coach? Well, you could count the FCS coaches that have moved up and been successful on one hand. Most of them recruit FCS talent. Does that mean you discount them? No. But there are a lot more Steve Roberts out there than there are Jim Tressels.
Is it a coordinator from a bigger school that has never been a head coach? Many discount that because they'll tell you it hasn't worked here. They'd be wrong in my opinion. If we had the bowl setup back then that we have now, Nelson Stokley would have been bowling multiple times during his career. And, while Rickey Bustle didn't get the Cajuns to a bowl, he got the program to a position where six wins isn't good enough.
Is it a coordinator or position coach at a bigger school that has been a head coach somewhere? Well, in that case, you have a record to look at. But it doesn't always mean success.
Is it a position coach? That got us Jerry Baldwin.....but it got FIU Mario Cristobal, who just won the Sun Belt.
There is no tried and true formula. You find out who is interested, you do the interviews and you make your decision.
Is it a high school coach? No. It isn't.
Fans (that includes me) need to worry about "we don't want soandso because he's never done that" and understand that whoever we hire, it just might work out.