While coordinators are able to have an influence on these areas in real life, their primary task is to play-call. It's not the case in the Madden 22 coins.
As you can see from the above screenshot, Matt Nagy has both an offensive and defensive strategy assigned to him. If the Bears were to make a change in their defensive coordinator, the defensive system could, at a minimum, stay in the same place. If the plan of a team were to alter based on personnel hirings or firings and firings, it could add variation to the user's experience and help to keep the system in a fresh state.
Capturing the game-planning aspect of football is nearly impossible accurately, so it's tough to blame the Madden devs for choosing a system that allows in-game attribute boosts on certain games.
A successful game plan does do not make players better at particular aspects of their game. It is more about putting that player in situations which allow him to perform his job better , through better play-calling. If my top corner can't keep their best receiver in check no matter how much we concentrate on man coverage for the week, we're never going to be able play a whole lot of Cover 1.
One way to capture that more accurately could be to force users to cut down on the options of plays and formations they're required to play during a given game. In other words, if you're up against a team excels at defending the inside zone it could be a good idea to choose more outside zone run plays within the game plan.
This could be another way to Mut 22 coins the role of the coaching team. Being able to hire a better-rated coordinator may enable you to add more of the games you schedule every week. If you have a poor-rated assistant, it could restrict your play-calling possibilities.