Underhill: Saints are interviewing probably 12 coaches (Tracker: officially 9 candidates) [Rapoport: Saints may add more]

This is a very simplistic take. And actually beyond the point that I was making. But whatever.

Can you identify any specific adaptations Payton has made to his scheme? Not saying he hasn't (he has). Just curious if you know what you're talking about.
Your point from what I got is that Payton and Gruden's system is basic compared to Reid's and the others you mentioned. I don't agree, Reid's system is not compared to Payton's. SP from the time he became HC was an innovator , subbing out whole skill player packages. SP even adapted later in his time here to more short passing game
My comment about Reid treading water was that he didn't make adjustments until Mahomes was a starter.