Look at the Patriots' stats for the glory years of their defense -- 2004 or one of the years close to it. 2004 New England Patriots Statistics & Players | Pro-Football-Reference.com Most of the sacks came from OLBs. Most of the rest came from DEs. A few came from interior DL (and we can't know exactly where who was lined up on which sack play anyway), ILBs, or DBs (especially Rodney, but he was often an honorary LB anyway). The sacks were of course distributed among a lot of players. But they also were concentrated at the classical pass rushing positions. That doesn't mean scheme can't substitute for pure pass-rushing talent; I think a significant fraction of Vrabel's or even Willie's sacks came when they were essentially unblocked. But if the OLBs can't rush, the Pats are not going to get to the QB pleasingly often.