your SF is trainee is better than mine :(
but anywho...
After 2 seasons of training PG's with your SF playing a game in the PG spot your PG's will be pretty good, asuming their the right height/age/potential/trainer level.
However, training a SF, from my simple understanding, will need to be very well rounded, and having your SF learn guard skills for 2 seasons, then have his training slow down, then get bigman training may not be the best idea. This will eventually make him unrounded.
You can still go ahead and train him for a few seasons, he will end up pretty good, but not totally well rounded.
Anyone who has a better knowledge of this matter please correct me of my knowledge.