The game doesn't have that depth.
To give more personal orders to players
For example , one player to shoot more, the other passing more.
To pass crossings at higher ground for a header or lower pass
and so
The length of the players, in my opinion, is the helper ST? Or a scorer? I think you gave me the clue. Maybe you're right, the game doesn't have that depth. Maybe I'm under the influence of FM 2012