I think that if Ish Smith had been with that team all year, perhaps a guy like Zeller could have done OK.
Thing is, Zeller looked pretty good in 2014-2015 when the team regularly played him in small lineups and he could just rim-run.
In 2015-2016, he started out the year getting shoehorned into lineups that basically featured two centers plus at least a couple of poor shooters (Smart / Turner / Crowd), and he struggled.
A guy like Zeller, who really can't create offense for himself and needs room to operate so he excellent speed / coordination / hands are able to outshine his lack of superlative length, explosion, and finishing strength. I'm just not sure he'd necessarily be in that kind of situation if he were in Philly.