I think that team would struggle to win 30 games, honestly. The scoring from the Big 3 just wouldn't be enough to prop up the abysmal offense from Rondo and Perk.
Remember, three members of that starting lineup have suffered career-altering knee injuries since early 2009, when that 5 man unit was at its apex.
How about this for an idea -- since Pierce and KG are both probably playing beyond this year, how about the Celts try to sign both for a few million each this summer?
KG as the 4th or 5th big and player-coach (assuming the Wallace role). Pierce in a Posey sort of role playing the 3 and 4 off the bench 20-25 minutes a night and helping the young guys maintain composure late in games, as he's done in Washington.
Celts aren't winning a title anytime soon, but that could be a cool way for those guys to finish up their careers.