So basically, the offense is going to go through my best offensive player regardless of what offense I choose? I am playing a lot of push the ball right now.
Your players will try to take the best shot possible (which depends on both their own skills and the skills of opposing players) -- and therefore your "best offensive player" can change from game to game, depending on who's guarding him.
This is something which depends to an extent on tactics (outside-focus tactics typically lead to more outside shots). Of course, your players are not perfect, so occasionally someone may take a stupid shot (less experienced players will do this more often).
But in general, even if you do something monumentally stupid with your tactics, your AI coach will try to fix the mess as the game goes on -- though his fix will never be as good as in the case when you player the right tactic to begin with.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."