heres why:
You use your NT or your zero, or whatever you want to call him to force the double team off AD. He does this by sliding over to the shoulder of the center that is closest to AD. With AD in a 3 or 4i (directly over the OT) it in theory forces that OG to help his center block that shaded NT. Freeing up AD to 1 on 1. If you were to move AD to the 0 or NT spot. He is always gonna draw a double team.
Morris is running some of Staleys 5 fronts with a NT, AD in a 3 tech spot, the other DT in a 4 tech over the OT and 2 stand up edge rushers outside of the TEs. That should force 1 on 1s across the board. But what Morris isn't doing is varying his fronts to the extent Staley did. Staley did some pretty crazy stuff with his fronts and who they rushed and who they dropped into coverage. This gives the advantage to Morris in run defense to some extent, but as far as generating sacks, Staley wins.
Don't waste your time looking back, you're not going that way. - Ragnar Lothbrok