I don't see how they could make room for two max FAs without going way over the cap.
Griffin would have to re-opt-in and get traded to the Celtics.
The way Ainge can make two stars work is to trade for one and sign the other as a FA. He has the assets to make a deal, but right now, there is only one option--George.
Griffin only comes into play if they can't sign Hayward. And I think they have a much better shot at Hayward than Griffin.
If Ainge really wants to beat the Cavs next year, he has to trade for George.