Hi,
I want to make the following proposition for upgrading resource nodes:
As opposed to the current system, where upgrades always just give you the resource, one could add a choice. For example, horses could either be bred for war (like now), or be used for meat (extra food), or be used for production (extra production). One could also use metal resources for industrial purposes, as opposed to solely military ones. For shards, it could perhaps be possible to add a choice between getting the shard and getting additional essence.
Crystal and gold could be used for unrest decreasing jewelry.
One could go even further, with some specific resource upgrades requiring certain town types. A Fortress could totally get a wall of steel from an iron ore etc.