Can you perhaps provide a source describing these groupings? Sounds like some kind of Poisson distribution, which might not be that unusual for randomly distributed geological objects in an event bed. I'd be particularly interested in a body distribution/orientation map for either Pompei or Herculanum. The reason I ask, besides pure curiosity, is that perhaps the body distribution might be affected by the rather violent geologic processes related to the pyroclastic flow (or then again, perhaps it might not). A map of body distribution and orientation might say a lot.

Biostatistic analysis of group animal behavior from traces or fossil/body distribution/orientation is a thing, applying to human body distributions should be feasible in the right circumstances. It would be fascinating if there was indeed some preserved palimpsest of human behavior preserved in the body distribution/orientation from the Vesuvius eruption.