Reffers to other football manager games e.g. Galactical Soccer Manager, when you have to choose soccer player that GM has give you right to pick available player, I think that physical and mental are needed as possesion for a team.. So that in my opinion through their stats in that game, striker needs attack points equaly with physical & mental, mid player needs to balancing attack, deffend, and physical & mental, deffender needs def and physical & mental skill points equally, while GK only needs def skill points + special ability..