Just an idea. But would be interesting to see a team alternate playing games between a +5 and a -5. Then compare the effects of all the - games vs. all of the + games. I.e. Opp 3%, Opp FG%, Reb Margin, TO's, Steals, Fouls, etc.
Note: I would use the alternating between the two settings to try and minimize the effect that player improvement might have on the results. For example if you ran +5 for the first half of the season then -5 for the second half you might EXPECT different results due solely to players improving.