I don't hate the idea.
Pierce's same MPG gets condensed. I have felt for a while that Pierce sits too long on the bench in stretches and gets out of rhythm. Start JG and bring Pierce in at the 6 minute mark (Pierce at the 2 or 3; maybe leave Jeff in depending upon the match-ups and Jeff's play). Pierce then plays 15 out the remaining 18 minutes in each half, and plays some of it against lesser talent.
I do think this makes our starting lineup a worse scoring lineup, but a KG, Sully, Green, AB, RR lineup can play D and rebound. Pierce, Bass, Lee, Barbosa, and Terry can all score off the bench. Still need another solid big along with Wilcox.
I think this shakeup may be worth a try.