Jerry had a good blueprint when he first bought the team; hire a football coach/talent-evaluator you believe in (J&J also had a history as teammates on the 1964 Arkansas Nat-Champ team), give him free reign over football operations...and support him 100%.
While realizing Jerry’s ego couldn’t let Jimmy get all the credit for long, which is why he ran Johnson off, Jimmy, who had to have been well-aware of Jerry’s ego, might’ve once in a while mentioned publicly that he worked for the best owner in the game.
Maybe if Jimmy woulda stayed, he mighta won a couple more SBs...and history might today view the Jones/Johnson/Aikman Cowboys like they do the Kraft/Belichick/Brady Patriots?