Helm Strap in Athena\'s statue

[Tarbicus]

Why couldn't an 'attached' arming cap be seen as both that and a functioning chin strap? It could still be rivetted to the helmet (or tied) at the points indicated, but be easily replaceable, and keep the helmet stable. It would also fit with the first picture posted where material has clearly rolled up beneath the helmet when lifted, but that would mean it was attached somehow to the helm.

I have an arming cap for my Roman Gallic helmet that covers the cheeks. If I thread the ties through the cheekpiece tie rings, as well as use the usual thongs, it helps keep the helmet much more stable but I can still remove the arming cap.