I think it's a misconception to say that Josh McRoberts would be unnecessary because he has a game similar to Boris Diaw's-- their main similarity is in being great passers, and McRoberts actually has a better assist to turnover rate than Diaw or anyone in the entire league other than Chris Paul, which means he has a better assist to turnover rate than 29 of the 30 starting point guards and all of the back up point guards in the NBA. That's a pretty impressive accomplishment for a 6'10" power forward. Unlike having too many scorers, there's really no such thing as having "too many" good passers on the floor at the same time. Not in the Spurs' system. And it's clear that the Spurs feel this way too, because they drafted Kyle Anderson, who is yet another player in that same mold.