I have started to run into a problem now that I control a lot of territories. I often have units deployed in territories and I have literally no idea where they are, this means I have to click on each individual territory to check if I have units active there or not, this becomes tedious when you own 58 territories. I think if you used a small indicator like this, you would be able to immediately identify if you have units in a given territory or not. You could also have another indicator (maybe on the top left) to show if allied units are active in a territory as well. This would make managing territories a lot easier and of course the harvester would not activate this indicator, because it is not truly your unit!