I think the FO and coaching staff has developed some sophisticated (?) theories about what combinations of talents, skills, personalities - and probably a host of other properties - that are needed to come together in a competitive football team. We will never know what those theories are, and they may not be valid theories. Time will tell.
Whatever those theories are, they've got to be better than just using gut feelings or guessing (see Oakland Raiders, for example). Gruden wasn't "into" analytics. So if a particular player isn't brought in, there's probably a good reason why. We'll never know that, either.
I think you have nailed what is going to happen
DT on 3rd down is perfect for the guy...... We need DE for downs 1 and 2 not named Turray
He was run over on run plays....... He is a perfect dedicated PASS rusher though and he could get 8-10 sacks in that role