It's incredibly misleading for people (And myself included probably once) to label these as communal as they are incredibly social animals, however, this specie, and many other Centruroides I've kept, will happily munch on others that are molting or weak. And if kept together at early instars, this is almost inevitable, and nothing out of the ordinary.
As adults, I'd say they're fairly safe to keep together, as long as they are well fed.