Well three things:
1) passing might be the single rarest of all skills in a big man. You can find a decent passer maybe, but a game turner? A guy who can run an offense? That's tough. Sometimes its easy to forget just how good Webb and Vlade were. Arguably the best passing C/PF tandem in the history of the NBA. Its going to be very tough to find even one guy at that level again (Brad is good, but not the same sort of consistent impact passer). KG could do it. There are a few other guys who have shown flashes here and there and maybe could step up.
2) Webb was the magic man in a way that is not often mentioned -- he was the guy with the skills to run the Princeton offense, but who did not HAVE to be a finesse player, and a cog in the system. He could also be an athlete, shotblocker, rebounder. Create on his own. He could play within the system but was not limited to it. That was invaluable and very rare. The system, like all systems, will break down from time to time. If all your guys are limited to playing within it, then when it braks, you're in trouble. The real trick is finding guys who can play outside the system if it breaks down, but who do not intentionally break it themselves.
3) Rick Adelman has not always run the Princeton offense -- his old Portland teams were great offensive teams without it. And of course its influence in Sacramento can really be traced to Pete Carril, who is quite old now, not in great health, and who has talked about returning back East to be closer to his family. So it would not surprise me at all if with the team largely disassembled Petey called it a career and returned home after this season. And if that happens, we might move a little away from the Princeton. Don't think we will ever leave it entirely behind as long as Rick/Geoff are here, but to run it at such a high level as we did for all those years requires some very specialized personnel which we may not be able to reacquire. And if you don't have them its kind of like trying to run the West Coast offense in football without Joe Montana and Steve Young. With average players directing it, it becomes an ineffective dink and dump offense.