My small headstone repair and full conversion to foam. My headstones are all hybrids of wood and foam. After years and years of repairs on the small ones, I removed the foam and will now install them on all full foam bodies.
I think the small effort to standardize your spacing will pay you back many times over. All you really need is a stick with two marks on it, or you can get fancy and drill guide holes in a board. Then when you're setting up you can just give someone a hammer, the template, and a stack of rebar and turn them loose.
