Flores is a LOT like Belichick, and that's a good thing. A throwback, old-school hardass who can cook up some absolutely confounding defensive schemes.
With that being said, the Cowboys are the last time that he would go to. He lost his HC job in Miami, during a stint that was otherwise going well, in a political fight with the owner. Flores told him that Tua would never win a Super Bowl, Ross told Flores that Tua was The Guy and to make things work. Flores pulled the "him or me" card and got forced out.
Jerry plays favorites just like that, and there's no way Flores would deal with that again.