Two types of building sites;
“flat” for farm, training camp and mine.
“ruins” for forge, both storage and house.
When a building is moved the empty site becomes a “ruin” type and will not take a “flat” building.
When a new area is opened up and someone moves all of their [xxx] into the four new spaces, they will not be able to build farm, training camp or mine.
I know that WHEN THE GAME IS FINISHED they all have the same possible buildings. This is before that.
If you want me to test it out, I have the spaces available, but if it screws up…then what?