As players, I don't think that Pierce and Butler are very similar. Pierce is a much better shooter(I base that only on the fact that I know that Pierce is a very good shooter, and I have heard that Butler is an alright shooter) I doubt if there is much of a difference in athleticism between the two though. From what I have seen(Not much) and heard(Quite a bit), I think that Butler will become a very good player in the league.