advice on modeling a flagstone patio

I’m looking to make a flagstone patio that will be exported to another modeling program (daz studio, poser) for use as a scene prop

I’m trying to give it as much realistic detail as I can before I resort to bumps and displacements so while I’m using flat planes on a image template for placement I want the stones to be layered and a little rough around the edges like real flagstone so I can get some closeup work with it.

Can anyone recommend a way to make “realistic” flagstone without bumps, normals or displacements and is the flat plane the way I should go?