One of the most bizarre combinations in recent memory has just been started in Dallas. Barring any other major moves it breaks down like this.
Rondo has an excellent assist rate- and the Mavs don't need it at all. Without him they were #2 offensively with an excellent TS mark (#4) and above average TO and Oreb rates. The Mavs offense doesn't run on one player handling the ball and creating an opening for another member to finish- it works on using Dirk to force Ds into odd positions and then exploiting the different assignments/rotations. Their leading assist man so far has been off the bench in JJ Berea (assist% 32), but among their starters their two guards were in the low 20s, and Dirk is at 13%. Their two highest USG players do their own shot creation, and dish out a few assists each as well.
Rondo's biggest liability is... not his shooting. Its his TO rate- over 20%- is really bad for a team that has terrific finishers. Giving up possessions without a shot when you have Dirk is just bad, as the better possessions that you gain from those risky passes generally aren't as good as Dallas' standard sets. Also not at all promising is that Rondo's TO rate was HIGHER when he played with Allen/Pierce/Garnett. The reduced offensive responsibility didn't lead to better decision making.
The one potentially saving grace is that Rondo is a monstrous rebounder for his position, and Dallas stinks on the defensive glass (#29). Rajon's career defensive rebounding rate is almost as high as the Mavs' starting SFs, and their total rebound rates are the same. That doesn't say much for Parsons as a rebounder, but it does show the impact that Rondo can have. 1.5-2 extra defensive rebounds a game over the Nelson/Harris duo could push the Mavs from #22 on D to the low teens on its own, without considering his on ball skills and high steal rate.
This is going to be a very awkward fit- Carlise has to reign in a PG's passing and shooting while emphasizing his D. This is going to be odd.