The thing about Rondo is, with a healthy Celtics team, he is not going to get those kind of numbers he put up in the playoffs this year, next year. It took some pretty poor performances by either Ray or PP this year to allow him to accomplish what he did.
So let's not go crazy over Rondo's talent. I do not want to trade Rondo or Ray Ray, but I honestly think the C's are still a contender for the title with either of them being replaced by someone decent.
Doesn't your argument suggest the importance of keeping Rondo though? Next year, Ray, Paul, and KG are going to be a year older and most likely will have pretty poor performances at times (even when they're "healthy"). So next year, we need a PG who is more than just decent to win a title...
except you don't need a PG at all to win the title, unless of course you think Derek Fisher and Rafer Alston are "PG's"
You don't need a pg, per se, but you need talented players aside from a very good big. It doesn't have to be a pg just like it doesn't have to be a sf or sg but it can be a pg. So while you don't always need a good pg, you can't always win without one. If you want to put your theory that you don't need a good pg to the ultimate test, go back to all the years where the winning team had a good/great pg. Players like Magic, Isaiah, Parker and Billups. Would those teams have all won the title with Alston or Fisher as their starting pg? If not, you need to go back and refine your theory.
The Spurs won 3 titles when Parker was an average PG, the fourth was the only year he was playing at an all star level. Billups actually was significantly more efficient and just overall better in the four years following the title run then during the title run (and was not an all star until 05-06).
Obviously Zeke and Magic were key, if not the key, player on their title teams. That is however clearly the exception, not the rule, and Magic was 6'9" not exactly your typical PG.
NBA Championship PG's - Rank as importance to team - Their league wide position
Rondo - 4th - Average (and that is generous)
Parker - 2nd - All Star
Payton/Williams - 4th - Average (and that is generous)
Parker - 3rd - Above Average
Billups - Anywhere from 1st to 5th - Above Average
Parker - 2nd - Above Average
Fisher - 3rd/4th - Below Average
Fisher - 3rd/4th - Below Average
Harper - 4th/5th - Poor
A. Johnson - 3rd - Below Average
It is pretty similar until you hit Zeke's Piston teams. PG is far and away the least important position when determining the league champion.