an idea i had would be since the game loves us getting materials for building sacrament could say “look we are pretty good right now so lets branch out” and set up mining and logging stations in old areas that you help create by getting materials to build it then you have this idea that you will have to go defend those areas when they come under attack payment for defending them would be you get resources like copper and wood or iron and the higher tier wood if you upgraded the logging and mining stations
you would be capped tho at like 3 per unless you upgrade it further it would still mean you have to go out and fetch the materials while keeping things fun