The forge needs to add an "ors" command to iron and coal if it is to be of any use at all. Couldn't build it until I captured a copper city.
<Building_LocalResourceOrs>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_COPPER</ResourceType>
</Row>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_IRON</ResourceType>
</Row>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_COAL</ResourceType>
</Row>
</Building_LocalResourceOrs>
<Building_LocalResourceOrs>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_COPPER</ResourceType>
</Row>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_IRON</ResourceType>
</Row>
<Row>
<BuildingType>BUILDING_FORGE</BuildingType>
<ResourceType>RESOURCE_COAL</ResourceType>
</Row>
</Building_LocalResourceOrs>