I don't really get Payton. He was worshipped in New Orleans. The franchise had gone to the playoffs five times and won only a single playoff game in its 39-year history prior to his hiring. He went to the playoffs nine times and won the Super Bowl with them, never winning less than seven games. He wasn't untouchable, but I think he would have survived a rebuild.
He didn't want to rebuild from ground zero in New Orleans though, so he just up and left in the middle of a contract, and then a year later gets bored with broadcasting (?), so he goes to Denver, where instead he can rebuild from ground negative one, on a team with $85MM invested into a sunk cost quarterback that is missing future picks because they valued him more than the picks. It doesn't make much sense.
From Campbell's POV I understand the mentorship angle. Campbell's playing career ended with a training camp injury on the Saints and Payton is who encouraged him to get into coaching, vouched for him to get the gig in Miami, and gave him a job when the Miami staff got fired. He wouldn't be here if it weren't for Payton, but he's also definitely not Payton. Payton is obviously a good coach, but Campbell I think is a much more calm and collected presence on the sideline than Payton, and I think the players like him more... You would never see Campbell yell at a quarterback how Payton did Russell Wilson. Even the officials, I've never seen Campbell lose his mind on the officials. Payton earned himself stupid 15-yard penalties with the Saints, one of which I remember costing him the game. And BountyGate? I couldn't even imagine a former NFL player like Campbell entertaining the possibility.