So just to clarify. If I have 12 people on the roster for the game and I start Bob the builder at PG and That guy at SG. Even though I have Bob the builder at starter, back up and reserve on the depth chart and I have That guy at starter, back up and reserve for SG the coach will put in a guy on the roster for garbage time even though he is not listed on the depth chart? So I can only have 8 players on the roster they all have to be on the depth chart at another position?
Yes. Any player dressed for the game can be put in by the coach, even if he's not on the depth chart. If you want Bob and That Guy to get 48 minutes, your best bet for that is:
PG: Bob-bob-bob
SG: That Guy-TG-TG
SF: player 3-player 6-player6
PF: player 4-player 7-player 7
C: player 5-player 8-player 8