Why is one of Wilfork, Kelly or Armstead likely to be injured in a significant way? You do realize that you are talking out your arse on that one. None of those three are Injury prone. Kelly lost time for only the 2nd time in 9 years. Armstead had the same sort of infection from his surgery that Gronk had. (And the surgeries occurred at different hospitals with different doctors). And, last I looked, Vince had only missed time in 2006 and 2009 with injuries that didn't keep him out of the play-offs.
Now, I'm not saying that they are going to come in and start all 16 games and play 90% of the snaps each. I fully expect a rotation.
That being said, only a massive fool who doesn't understand the game at all would sit there and say that Wilfork occupying 2 blocker doesn't help the pass rush. Lets look at a typical set. 2WR, 1 RB, 2 TE, 5 OL, and QB. If Wilfork is occupying 2 OL, that leaves an OT and TE for Jones, the RG for Kelly, the RT for Ninkovich. That leaves Collins, Hightower, or Mayo in a favorable match-up either against a TE or RB. Or, it leaves the potential for a CB blitz.