Don't think there's a completely right way to do it, there'll be people telling you either way is the best way to go. My leading scorer, assist leader and best form-player is Gerailton de Souza Rodrigues, a striker who I bought 2 seasons back. He's at 35 for Defense, 53.2 for Attack and 51 for PHY/MEN skills. Heavily powered in attack and physical/mental and doing wonders.

There'll be examples by others of players doing exceptionally well with more balanced skill-sets.