One comment I want to make on the Head coach, Coordinator, Position coach thing:
They are three separate skill sets, and being good at anyone of them does not ensure success at the other. Reference the Peter Principle.
Mike Singletary was a great position coach; head coach, not so much. Same concept can be said for both Steele and Shannon as Coordinators to Head coaches. It is also my reasoning as to why Gus Malzahn may not make a great head coach, but he is a great coordinator. On a side note, him going to Arkansas St for a first HC job my have been a smart move to get his feet wet.
Head coaches tend to be strong organizational types, CEO's. Coordinators are X's and O's guys, very analytical, nerdy even. Position coaches are motivators, rah-rah guys, recruiters. IMO, the best coaches, the elite are those that have a strong combination of the three.