Of course I would take them back as role players, it depends on how much they would want in their contract. If they both took say 3 mil a year to play for us then yeah sure. I wouldnt spend the MLE on either however.
Even without Pierce or KG they would be able to play a nice role on the squad. Would they catapult us into contention? No, only if Green, Rondo, and Sully became 2 superstars and one really great third wheel.