idea for mod, build to gain resources (if it does not exist) rol server

Hello people, first of all I apologize, I use Google translator, I’m from Chile, South America.
be brief, my idea is a mod, to build castles as seen in the photo below, which generate some resource or currency to market, in the merchant role server of the middle age.
as you will see, there are yellow squares on the map, the idea is that a reinio build a castle there, and generate X resource or currency, the yellow squares with stars generate more of this last.
I am working on a role server, I have several ideas and I wanted to know if this is viable. thanks for reading me