How nice would it be to be able to deploy or redeploy your workers amongst your upgrades? For example, if you have several upgrades taking place and have one lone worker, how about an option to add him to one of the upgrades to reduce the time or take two workers from another upgrade increasing that time but having the option to reduce another upgrade? If a building takes 4 workers 3 days to complete, why not be able to throw 12 workers at it for it to take one day - they are YOUR workers after all are they not?