You guys have implemented Collaborative Items, for example, the decorative vases that the Potter can make using metals acquired from the Blacksmith. The thing is, my town didn’t even have a Blacksmith yet when I was making these items.
My suggestion is to add a second requirement for these items.
Example: Decorative Glass Vase requires Level 4 Potter, 1 Clay, 1 Bronze(?) Bar if I recall correctly. Add another requirement of a Level 4 Blacksmith.
It helps with immersion, making your village feel more like an actual collaboration between professionals, and less of a “Due to hours of working with Clay, your Potter suddenly knows how to finely smelt and work with Bronze”. 