Dude. The hoplite aspis was single-ply wood with a millimeter-thin stressed bronze covering. For the sake of comparision the Italic scuta were three-ply wood with a hide covering on both sides, which is around as strong as wooden shields now realistically get - and weighed a ton.
Pila, far as I know, holed scuta readily enough - what do you *think* the Italians had mainly been throwing them at for centuries ?