I guess I have the roman fantasy of the metallic square scutum(?), when I did a quick read up was was made with quality layered wood and strategically placed metal trimmings and a metal boss at its center that served both in offence and defence

First thing I thought when I saw the centurion’s shield was if it was an auxilia’s shield, but it makes sense for them to have lighter equipment if they were meant to act as command officers and to inspire confidence in the ranks at crucial times