This is just another dumb rumor from a guy who loves to spread rumors, and that goes for Lombardi too. Here is the crux of it. If Jerry could hire Sean Payton he would. Wow, what a revelation. So would I. The problem is Payton is under contract with the Saints so Jerry cannot talk to him about coming to the Cowboys. And he would have to cough up draft capital to get Payton and my guess is it would be a lot. I don't think giving away high draft picks for a HC is a good approach. Since the Cowboys do not sign top tier free agency, high draft picks are more valuable to them than most teams.
But the dumb thing is, this would be throwing good money after bad. Payton is not going to fix the problem with Dak. Dak is who he is, which would be fine except Jerry paid him $40 million a year when he is worth about $10 million less. Dak's problems are in his head and while Payton may be able to make some minor improvements in Dak's psyche, I doubt he can turn him into Aaron Rodgers or Tom Brady.
The best thing Dallas can do to help Dak is hire an OC who knows how to design a running game. Put those high draft picks into offensive line and TE, and some WRs who can catch and block. Balance the offense so Dak does not have to carry the team on his shoulders. Yes, I know, he is getting paid $40 million but there is nothing that can be done about that for the next 3 years so accept it and work with it as best as they can.
Along with that, make plans to move on from Zeke. His 2022 salary is already guaranteed so he will be a Cowboy in 2022, but that does not mean he has to play every down. Draft a RB in the middle rounds. Look for someone who can run and block, and also catch a few passes out of the backfield.
Give Dak a lesser role and the offense will be better.
Then, stop overpaying your free agent players.