My wash box setup. The box is 18"x30" so one can see the size of the clump. This clump is 6 years old and is evident to me that it is due to be divided. "Peonies do not like to be disturbed" is far from being correct as far as my experiences have indicated. I do not intend to replant any divisions because I have 2 others appearing to be identical.
The last pic is the residue left over from using the water hose to loosen the roots in order for them to be lifted. Saves lots of roots for replanting if desired.