I would think that it would be more efficient to train him to become a guard (especially since he is already a PG). Also, your 4 youngest players are PG/SG so it would fit into your training better if you trained him as a guard. Respectable ID and average RB arent good enough for a SF, so you would have to train them, but it would be inefficient because of his height. On the other hand, you can't really ask for a better height to train guard skills with.