Perhaps I should elaborate more clearly. The authors argument was that those with previous head-coaching experience (at smaller or non-elite programs) have more success when hired at big/elite programs than those who were previously employed as coordinators at top tier schools.
Yes Knight Shift, you are correct. And there are outliers everywhere. However the thrust of the argument was that this is a more common occurrence than not.
It's interesting that neither Schiano, Flood, or Ash never held a head-coaching job before Rutgers. Obviously, that would not be the determining factor as to whether each would be successful. One could even make the argument that Flood may have not been as successful because, even though he was learning on the job - just as Ash is, he did not have enough assistants on his staff with enough head-coaching experience, themselves, whom he could learn from. That may be the difference between whether Ash will be more successful. Just a thought.