Its super easy to soft lock yourself, either by the lack of resource variety or lack of being able to use the stronghold as a temporary resource stash, either way the lack of creativity here can kill gameplay before it starts. I suggest looking at old settlers/stronghold games to get a better feel for the serf mechanics as I assume this is meant to be a developmental version of classical RTS serf mechanics, the player always goes into your game blind and shouldn't be punished for pushing the limits :)