People use bronze instead of iron, use ox-plows, and so forth. But it is a fantasy Bronze Age setting, not a historical one set in the real world. We have silver coins, plenty of writing, ship transport between the continents, and giant flying Crimson Bats.
In short there are Real World historical analogies to use, but they are just analogies and sources of inspiration – recognize their limits. Glorantha is a fantasy, not a historical simulation.
From time to time a few people try to impose historical simulation on Glorantha but it isn’t going to work. Use the historical world as a model, but know when to ignore it in favor of the fantasy.
Note that calling Glorantha “Iron Age” gets very misleading. First and foremost nobody except the dwarves makes widespread use of iron (and most bronze in Glorantha is a mixture of tin and copper).
Second and perhaps more importantly, the Iron Age is usually used for that transition period from bronze to iron, and becomes replaced by the “Classical Age”- the Achaemenids in Persia, Classical Greece, etc.
This historical straightjacketing is exactly what I was posting about.
Note that the Gloranthan “broadsword” refers to a blade like these: