It’s pretty rare for the New York media to give us an article with real football talk (Xes and Os) but here’s one focusing on Barry Cofield and the Giants DT position:
Spagnuolo for the most part is importing the Eagles’ defensive style, which means there will be virtually interchangeable left and right defensive tackles and no classic nose tackle. Both players will line up across from the guards more so than directly across from the center and will be responsible for stopping the run as well as getting to the quarterback.
Cofield will no longer be playing a regular nose tackle position where the center and the guard double team the DT. While this should give him a chance to beat guards 1 on 1, it gives the center more options. The center can help block one of the Giants DTs or get to the second level more easily because there’s no one directly in his way (at least that’s my limited understanding).