I think being able to establish trade routes would add an interesting layer on top of caravans and workshops by basically combining the two. They both just function autonomously and the money you make fluctuates pretty regularly. My proposal is to essentially set up trade routes, which would function similar to a caravan, but instead of just roaming the map buying and selling a random collection of goods, you would be able to select certain raw materials to buy or sell finished goods to other towns. This would reduce the dependency on production based on bound villages and allow the player to set caravans to buy and sell from specific places all over Calradia. It could also be expanded by allowing you to negotiate prices as well (obviously the higher your relationship with merchants, the better).