I imagine just about anyone can play for or coach the Bears teams. Offense and defense. Apparently the playbooks are there, in place since the early 60's, and never gather dust. Follow the books, and you will be a successful Chicago Bears coach/player.
You will lose a shit ton of games, and bear the ire of all fans/analysts/reporters, but you will be successful in that respect. It is Bears coaching/playing. It is 'in the books' of The Hallowed Hall.
And sometimes, as a player, you will just shit your pants. If you watched the game last night, you will know what I mean. 😉😲