OK, so taking the word "need" literally, i guess you don't need a superstar. But if I way were building a team with the intent of giving my team a reasonable chance to win a championship, I'd sell my soul for a bonafide superstar.
Of all the superstar-less teams in NBA history only one won a title. And that team was a one and done champ with a bunch of players who would be better than any current Celtics player. If any current Celtic ends up to be Chauncey , Rasheed, Ben, or even Richard Hamilton, I'd be pleased.
The 2004 pistons are Buster Douglas or Michael Spinks -- able to win a title in a perfect storm -- but not the blueprint you start with to build a contender.