Like I said, there are lower leagues where the BB player listed as Guard can easily be better than a Forwar or Center (just like in RL). But you do not see any 6'5 C-s or 7'4 PG in the top leagues (just like in RL).
What I am trying to point out is not the physical part of the game, but the mental. Why is it given that they already know how to run those offenses? And why do they know what and where to take the shots? This game should be just as mental as it is physical. My thing is that if you know or skilled to play a type of offense, why not get a boost.
Every basketball player can play in any offence. His experience determines how good he is in his decision making. Experience skill is present in BB. Still if you put a player with atrocius passing to PG spot and try to run Motion. He is going to make more turnovers, than passes. Perhaps if he has good exp, he tryes to shove the ball to SG and make him run the offence more.