I did some research on this yesterday while planning to start a similar thread. Here's what I found:
For the second year in a row both head coaches in the NCG have been born in Ohio.
Since the 2000 season 7 out of the 10 head coaches in the NCG have either been born in Ohio (Tressel, Miles, Meyer, Stoops) or were
OSU assistants (Carroll, Saban, Coker).
If you want to stretch this a little Frank Solich was born in PA but moved to and played HS ball in Ohio.
Only Mack Brown and Bobby Bowden have no ties to Ohio that I could find.