i agree with egg, try to teach himm everything :)
But i would depend the order on your other trainees, so if you train guards with him start with guard training, if you had promising bigs try to make them to PF and start primary with big men training. If you like to train 1 on 1 or JS with your guards try to make it for forwards or wingmen, because this dude also profitate from the additional IS training which is in my eyes one of the more difficult trainings for the "smaller" SF when you don't train it with those skills as secondarys.