Not for nothing, but Frazier's defense in Minnesota has been dominant against the run:
2009: 3.9 yards/attempt (T-5), 1394 yards (2), 5 TDs (T-1)
2008: 3.3 yards/attempt (T-1), 1230 yards (1), 10 TDs (T-6)
2007: 3.1 yards/attempt (1), 1185 yards (1), 7 TDs (T-2)
For comparison's sake, the 2009 Bills gave up 4.7 yards/attempt, 19 TDs, and 2501 yards.
It's about having talent on the defensive line and the ability to use it. If you get two or three great defensive linemen, it doesn't matter what scheme you play behind it. If the Bills hire Frazier, hopefully he's learned that lesson and will lean hard on Buddy to sign, trade, and draft the best DLs out there.