Well yes the more bigs you have on the field the better you do vs. Run. The problem is the chess match of sub package. So now you get trapped trying to cover a speedy receiver with one less defensive back. Looking back on those big Steelers defenses you had a big nose that couod still get after the Q. And you didn't have to sub all the time. You also had a DB that played like a LB so you had way more flexibility. But those players don't grow on trees.It was not a coincidente that the defense improved against the run when playing with 3 big DTs upfront. Call it a 4-3 if you want to see Watt as a DE but the truth is that without 3 mammoths up there the team was getting gashed on the ground. Whether it was Leal as the 3rd DT or Adams or Wormley it helped a lot
The D needs 3 DTs up front in early downs and short yardage situations.