This is where you need to expand on your comment.
I agree that the game engine decides the game without the input of the managers during the game. The game engine takes all the info of the formations and players before the game starts, hence the lockdown with a few minutes to go, and simulates the game and then creates the commentary which can be manipulated depending on what the manager does during the game presenation.
So formations are still relevant, it just doesnt matter if you change it after the game starts.