When you decide to move the others this fall, you should divide them too. You'll have happier and stronger plants for it in the long run.
I have about seven that I need to move somewhere this fall. Of course, I've been saying that for three years now. I just need to get the bed ready NOW so that I will actually move them this fall.
LOL I'll get there.
Of course, I'll probably have several new ones to put in the ground next to them. There is nothing like a Peony addiction, unless it's a Lily addiction, or an Iris addiction or worst of all, a Hosta addiction!! *ARGH*