So who is going to train one position in this scenario?
Nobody. I meant they should replace one position training with two position or maybe allow you to train an inside and and an outside skill every week so you can train guards and bigmen at the same time.
Why not disconnect training from positions completely and allow any player on the roster to be trained at the 1-position level in any skill a manager wants each week? Train your PG in rebounding, your SG in FT, your SF in stamina, your PF in handling and your C in passing if you want.
Besides, last time I checked basketball involved 5 players on the court for each team. At a minimum the fastest level of training should allow you to train 5 players per week not just 3. No wonder there is a shortage of properly trained players.