Charr economy
Not too sure about the specifics myself. I do know that in one zone, I believe it is the Fields of Ruin there is a heart quest where you have to take the roll of a slave task master and “motivate” slaves into mining ores for the Iron Legion. I’m sure they use methods like that to get some of it and I would assume that the Blood Legion could be sending supplies from the west.
Im pretty sure they were criminals and prisoners, not slaves.
The charr are heavily industrialised. They do pretty extensive mining.
Also remember that the charr are built like a single military organisation. Although charr are given a resonable degree of personal freedom they still are part of a military organisation from birth. The Iron Legion would own most of the mines and control the flow of materials through Ascalon. The Iron Legion also now exports its skills giving it greater sources of income.
Having said that I suspect you would find the Blood Legion and Ash Legion Citadels werent built of metal. I suspect their homelands are less industrialsed and more built around their Legions core strengths.
The char do come from a region that has lots of mountains which contain lots of ore. It would be the same for the norn if they were into mass mining.
They get a huge amount of ore from Iron Marches and other charr zones, where they have dredge and others working as slaves.
Back when the Flame Legion was in charge, they used their magic to bring countless ore deposits to the surface so they would be easily accessed instead of having to build huge mines to search for the veins. Luckily, this happened all over the world, which is why you see chunks of copper sprouting up everywhere like mushrooms.
And a man who trusts no one is a fool.
We are all fools, if we live long enough.”