To be honest these sorts of things often starts fights and lead to eventual DM ...
if they add a new marker anyway it would be great if there was a policecar spawner and an arrest marker cloose to the farm since there often seems to be many wanteds there and most of them complain when they get arrested and have to wait for the cop to run the whole way back to the PD since the policecar always seems to be completly destroyed every time a cop visit the farm. Mabye somewere outside but not too far away, the yellow marker is for farmers and the blue could be a small PD.
I think would be enough if a worker only can spawn a combine when the corps are ready.