I suspect the definition of "full personnel control" is something that varies a bit, and must be negotiated.
If it means that a GM is little more than an information gatherer and the HC evaluates and makes all the picks autonomously, then I don't like that idea in modern football; there is simply not enough hours in a day.
If it means that the HC has veto power over draft picks and FA pick-ups and decides the roster at every stage and level, then I have no issue with that provided it is a good experienced NFL HC with a winning track record. Gruden has that.
I would never give that to a David Shaw, a Kyle Shanahan, a Josh McDaniel.
I'm on record as saying that I believe Stan will ONLY look seriously at guys who are now, or have been, HCs.....preferably in the NFL but secondarily in large college programs. I just don't think he'll do much more than interview NFL OCs and DCs for the sake of information gathering, and perhaps satisfying the Rooney Rule. Or in case he can't find a HC that is willing to take the job on his terms.