I think Lowry being out is having a bigger impact than Bargnani's absense..
The PG is the backbone of the team, the leader, he's in charge of running the team. When you have a guy who looks for his own shot and gambles on defence, that type of play eventually spreads throughout the team and it becomes chuck city, with each player trying to get his own.
With Calderon, he's looking to set up his teammates at all times, and his shot is only "if necessary" like in a deep shot clock situation. His play spreads through the rest of the team, and players give up shots looking to set up teammates.
Ed Davis has shined, and his offense is really improved. I think he's probably good enough to start, so either Bargnani
is 6th man when he comes back, has an extremely short leash as a starter splitting even minutes with Ed, or you ship him for some needed depth or a SF. I don't think Pietrus is the answer as a starter.