I think Pierce needs the KG tonic. Reduce minutes, get him better match-ups (for KG that was moving to Center) and keep him rested as possible.
To me there best play is running back KG and Allen on one or two year deals, Bass picks up his option, and Green signs for a two year deal.
KG, Bass, Green, Allen, Rondo with Steisma, Wilcox, Pierce, and AB off the bench. If they could improve from Wilcox to a better big man, that'd be ideal - but they need a 4/5.
Of course Bass, Green, KG, and Ray may all end up impossible to re-sign. I think that's their best hope though.