Orc Bone/stone versions of metal for more consistent tech level

The overwhelming majority of the assets imply stone-age level technology, but a few of them have relatively advanced metal work (Steel blades, steel banded shields/barrels, and steel plate walls.) Could we either have some stamps to represent how they make these things, or perhaps have bone/stone (or at least bronze) versions instead to keep the tech level consistent? Also, stone spears and arrows would be the most prevelant weapons in this tech. We could really use them in this set.