 Also the Romans used the pila, while Greek troops tended to use local variations of Javelins.Also similarity of equipment in regards to helmets and chain-mail can be explained by Celtic influence experienced by both the Greeks and Romans at a similar time.In this sense, we can only assume that the Hellenistic kingdoms did reform and re-organize their troops in some regards along Roman lines, but these appear to be superficial at best and quite possibly the result of convergent evolution, with both cultures influencing each other.