Efficiency isn't the rank of players, first of all it takes no account to defense, and also it doesn't take into account MPG. In addition to that, big men always get an advantage over guards because they shoot higher percentages, and it's easier to get rebounds than it is to get assists, which is normally the difference between big's and guards statistically.
Anyone that thinks efficiency is the rank of players doesn't know basketball, sorry, but it's true. So Brad Miller is the 11th best player in the league?
_________________
While I agree that efficiency isn't the rank of players, really think now, a player wouldn't be efficient if he wasn't putting up good numbers in a variety of categories... While I wouldn't say Brad Miller is one of the top 15 players in the NBA< he is one of the top 5-8 centers > He's not THAT far off. Last year he was injured half the season, and he still put up 15 and almost 8 and 3-4 assists.
But yes, you are correct, efficiency ratings do NOT fully determine the rank of a player, but I do believe it should have some part.