For all of Zach's warts (and there are plenty) he's a far more effective player than Rudy (neither plays much defense so I leave that out of the comparison)
in general (not just concerning these two) bad D from an inside player is far more detrimental then bad D on the perimeter.
On the other end, when Zach was in Portland I argued forever that he should be utilized off the ball working the offensive boards... he's a monster in that role. Unfortunately thats not how he was used/how he played as more and more he epitomized a selfish black hole. Zach on 5. Good team offense is largely dependent on spacing and both Zach and Greg looked to be on the low block. That's not why ZR was shipped out, but they didn't project well together. Conversely Rudy's offensive game has been very team oriented. He moves the ball, runs his man off screen after screen and spreads the court with a high percentage deep threat. Hopefully he enjoys a run of good health and we get to see how good he can be.