I'm not sure that is true. Jason Williams was a pretty dynamic player for awhile. Might very well have been a better fit next to Wade than Rondo will be next year (given Williams was a respectable enough 3 point shooter). Williams was the starting PG on Wade's 1st title team and for a number of other years (that title team also had a very old Gary Payton backing Williams up). Now obviously the James/Wade/Bosh teams didn't have very good PG's, but Dragic isn't exactly a slouch and again with his shooting is probably a better fit with Wade.
It has also yet to be seen how good the Rondo that will play with Wade this year will actually be. He isn't exactly a young guy any more, though is coming off a career high for 3PT shooting so perhaps is finally becoming a more well rounded player.
Rondo probably is the best PG Wade has played with, but I wouldn't just write Williams and Dragic off given Rondo is 30 and has never been a good shooter.