If Lebeau was still here, Shazier would just be just starting his first full season and Burns wouldn't even get some part time reps until next year, his 3rd year. Players like Sean Davis and Hargrave would easily be riding the pine still. Cameron Heyward did not actually start the full year until his 3rd season.
Just because you innovated a 3-4 defensive scheme does not mean you know everything; worst thing about him is fraternization with the veterans (giving them reps over younger players that are already ready to play). He was innovative but FAILED to evolve with opponents who have evolved to counter his scheme.
Thank God he's not the DC anymore. Good riddance especially the prevent defense which unfortunately Butler has somewhat inherited from him. It's mind numbing when someone does it over and over again when they keep failing at it over and over again.