The only kind of coach who Jerry will allow to be a true head coach (i.e., free of Jerry meddling, undermining, micromanaging), is a head coach who already has an established history of obvious success that demands respect -- even from Jerry.
The problem is that this particular kind of coach is likely to be past his prime by the time he starts over in Dallas.
And yet the other kind of head coach, the one who will be forced to endure Jerry's meddling, undermining, micromanaging - won't have much of a chance to succeed, because of Jerry's meddling, undermining, micromanaging.
I think the Cowboys' best chance of success occurs under the aging established coach who keeps Jerry in check.
Dallas just isn't the right situation for the up and coming head coach with loads of potential but marginal experience. Jerry would stay in this coach's way, constantly flubbing up the whole deal.