I have control of a bunch of flats around me, just not those two. I didn't even think of the idea they used. It all makes sense now though, why they didn't declare us hostile immediately. They didn't want me to see the red. It was only by complete chance that I was caught off guard by the appearance of a new low level city bearing their flag. When I was asleep though I was hit with surprise 1 scout takeovers of all my valleys, which is how I knew we were getting targeted.