Let's see of the four coaches who never played college ball:
Leach- one of the most innovative offensive minds in football, probably better suited as an O coordinator, but has brought consistent bowls to Tech
Mangino- finished arguably the best season even in Jayhawk football, competing with big boys in big ten at a hoops school, damn good coach
Johnson- turned a consistent loser into a winner at Annapolis, broke streak against Dame, as solid as they come
Weis- verdict is out, was God-like first year, then came crashing hard with inexperienced players
So you have two really good coaches, one very solid offensive mind who has been successful, and one undetermined at this time.
For the small sample size, I'd say that's a pretty good measure of success.