Here is a new Factbook video on how most of the weapons in the world of Overgrowth are made:
There are rare cases where other races make weapons, like how the swords in Lugaru were made by a rabbit! Because the steel is harvested from the crete, there is no need to melt iron ore in a blast furnace and mix it with carbon. This means that the technology and expertise needed to make the weapons is a lot lower. Many groups in Overgrowth are still figuring out how to design effective weapons and armor, and so sometimes their gear is pretty primitive or unusual!