No. The Roddicks and Safins would own Djokovic and the Gonzalez/Blakes would toy with Nadal off clay.
Roddick no. Even if his peak level certainly is underrated on this forum (and I say this as someone who dislikes duck), Nole would win at least on these slow courts. Peak Safin is not inferior to Nole 2.0 though. Too bad Marat cared more about women than tennis.
As for Gonzales, we've already seen that he could destroy Nadal on a good day. Blake as well, but James' game was horribly inconsistent, even more than Gonzo's. Nadal on the other hand, his biggest asset is consistency. My guess is he would beat them more times than not. But even so they would be big threats to him.