Hey there! Here’s something for you!
How about having thralls at the workbenches “harvest” simple materials on their own, like twine, iron, stone, etc. Have it go along with their tier as to the resources ( i.e. t1 Smith harvests iron bars, t4 Smith harvests hardened steel)
It always surprises me when you’re at level 60 and you just need some damn twine lol. Can’t someone get that for you? You have a Castle filled with slaves! No one cared to gather some twine?!
It shouldn’t be a lot of resources, maybe 5 an hour and a Max of one full stack (if there’s a full stack they won’t harvest more). And nothing complex, just those simple things you seem to always need. Nothing like black ice or silver and gold.