Then who are Murray and Nadal?
Those 2 are some of the best returners in the game...and are also able to control rallies.
I can think of a great many compliments to pay Nadal but he really, honestly, truly, isn't one of the best returners of the modern game. On clay, yes, but if you look at his statistics off that surface, he really is a pretty poor returner (by the very highest standards, of course.) The ATP published some statistics and he was well down. Federer and Davydenko are the best, with Federer the more impressive because he plays far fewer second division tournaments.