To win a championship, pretty much yeah.
The only team I can ever recall winning a chip without one was Detroit in 2004.
I agree that team had no true stars, but they had so many really good players, just below star level—Chauncey Billups, Rasheed Wallace, Rip Hamilton, Tayshaun Prince, Ben Wallace (really good defensively). The only current Celtic who might be at that level (offensively, at least) is IT.