An Idea which I think would make it so much easier for us to manage our little guys would be the ability to limit how many workers/farmers work on a building/farm.
So say instead of having 2 farmers work on 1 farm. You can limit the amount of farmers on that farm to 1 farmer and the other farmer will go work on another farm.
It would allow you manage them and get them working in a more efficient way and should help put a stop to the workers constantly racing each other.
Just an Idea.