Don't know if there's a valid answer... I give you mine.
Did you noticed for example speaking of MCs that some of them have better defensive attitude, while others passing attitudes. I mean when you assign skill point the players develope their ability in different ways: you can have an MC with 46 tackles 46 marking 44 position 46 headshot 40 take and others with 44 tackle 45 covering 48 marking 44 headshot and 42 take.... so, but that's just my theory, if you gave a look to the skills you can find the player attitude (more offensive or more defensive) and the position where he may perform better
In italiano potrei spiegarmi meglio