You are correct that it helps to have that big you mention, but 98% of why we are playing zone is we have no bench. Next year we will have a bench, so we can play more man to man and not worry about wearing players out.
Mik and Sam tend to accumulate fouls in man to man situations.
MM has never really demanded that defense be played. She needs to take some of the blame for why ND has not been a strong defensive team. Last couple of years she just gave up on pushing it knowing that ND could outscore just about everybody it played. Does she want to emphasize defense going forward, or not?
Mens Basketball
Football (defense appears to be getting better)