I like the whole idea very much, but I still think there is something missing. It's happening quite often with me me and some friends that we have a good player that in the middle of the game ends up going to another position, and then he gets stuck there because nobody is better then him to replace him, and then he never goes back to his original position, in which he is much better.
I think one solution would be to add a feature to allow us to set in which positions each player can play. For example the options could be: PG, SG, G (PG/SG), G/SF, SF, PF, F (SF/PF), C, PF/C, F/C.
Another (more simple) way, would be to establish that as a rule in the game, by position, and not specificaly by player. For example, a player put in one position in the "set orders", will be able to play only on this ones:
PG: PG / SG / SF
SG: PG / SG / SF
SF: SG / SF / PF
PF: SF / PF / C
C: PF / C
Still following all the same engine already working, just including this restraints. Just a suggestion..