Try to sign Mathews/Leonard/Butler (Mathews at around 14 per year, offer Leonard (near-max) or Butler (the max)). I think Butler would be matched but Matthews or Leonard is a possibility. Then sign Pierce as a 6th man.
No thanks to Matthews at 14m a year with him having just torn his achilles. Players usually have problems coming back from that. Butler and Leonard will be matched at a 99% probability.