Armor question

[Matt Lukes]

Indeed there are a number of instances of shoulder flaps not looking like they're made of the same thing as what the main armor is- the Adamklissi Meotopes and the grave stela of Sertorius Festus come to mind immediately, but sculptural depictions are dodgy- who's to say the sculptor just decided not to detail those bits? Certainly there are many depictions where the flaps are clearly the same armor- mail or scale. It may be that some non-armor versions of flaps or doublers did exist, but it's surely problematic to demonstrate it.