Now it could be a big deal but there could be a lot of factors that could lead to the bones finding themselves in one grave. It could be a natural occurrence, humans in Roman times just gathering bones for scientific research, or it could be a case of political play and so on. It can be easy to identify who (like in the case of the woman), where the bones came from, and when, but identifying why the bones are in one grave will be a very difficult question to answer