Isn't Temperament connected to how likely player is to cheat? The lower Temperament the bigger cheater? Players frustrating opposition by kicking them and diving and winning penalties (at a chance of getting booked instead) might lead to results improvement over players who never cheat. And Model Citizen having high Temperament even if it's detrimental to performance on pitch makes sense too, you wouldn't want your Model Citizen to be a cheater.