upperclassmen at all key positions + built in energy/passion of being underdogs and getting a new chance.
Despite Weis's experience as a position coach and brief HS coaching experience, it seems that he didn't sufficiently emphasize fundamentals in the subsequent years.
Weis also lost his motivating mojo over time. Maybe the Jersey tough routine wore thin over a longer timeline with college aged players. Maybe he was impatient to backfill the holes left by Ty's recruiting.
By impatient, I mean that Weis shot for the moon instead of playing it steady (somewhat in 06, heavily in 07), hoping that his offensive schemes would mask youth or weak depth at positions. After that he just kept doubling down and it never worked. Eventually the 09 team, on paper, had no excuse losing more than 3 games and should've been a BCS squad... but obviously came well short of that.
I wonder how things would've played out if Weis inherited 4 classes with at least average (for ND) depth. Would he have been able to be a more steady hand at the wheel during '07-'08 while reloading from the Quinn era and getting his elite recruits experience? Would that have opened up more room to focus on fundamentals?