I think it depends what kind of 3-4 is being run. NE's 3-4 uses a massive NT in Wilfork which works very well there, but you also have Dallas' 3-4 where Ratliffe is the NT and while hes not your typical mammoth NT, hes still very effective. I think that kind of 3-4 is more prdeicated on having a penetrating line than a bunch of behemoths that hold up the blockers.