In OP's case, not really. However, sometimes, if all three transfer to a 4th partner - for example Marriott Bonvoy, you can play games and transfer in and out of a hotel program, and then into each other. For example, if you have UA, SQ, and NH points, all of them (from what I remember) are partners of Marriott, and all in the same Alliance. You transfer points from programs 2 + 3 into Marriott, then transfer everything from Marriott into program #1.

Obviously, this creates horrible value, but at least it's better than seeing them expire, I guess!