I think this is why so many coaches fail.
Just like in any business, innovators succeed and the people that come behind them and copy what they did usually fail.
The most common concept in NFL coaching searches is find the guy who worked under someone who was innovative and successful. And what you get is a watered down copy cat that doesn’t really understand how to build the system.
Look at our defense. Mayo and Covington worked only under belichick. But they simply don’t understand the system at the level needed to run it alone.
Joe Brady was handed a talented offense, and has done a good job calling plays within someone else’s system. He was terrible in Carolina and now has less than 2 years as OC in Buffalo.
Had he developed players, brought in a new system and turned bad to good, he would be intriguing but he really hasn’t.