It's not just Rondo's talent level-which is quite questionable right now anyway, it's his fit.
As this roster currently stands he doesn't make much sense. We've got no decent off the ball shooters at the 2-4 and he kills spacing as soon as he gives up the ball, which is a problem in both Cuz and Rudy postups/isos. In Boston didn't matter as much as he controlled the rock. Part of his issue in Dallas was what happened as soon as he gave it up, which was his man sagging 5-10 ft off, almost ignoring him. Here, Rudy/Cuz will be seeing a lot of the rock.
Combine that with WCS, no consistent shooter at the 2 and Rudy who's not a good catch and shoot guy, the fit is highly questionable....as this roster stands.