This is an observation I made at xb1 NA Haderus last night.
The entire imperial city was yellow, so me and two other random reds run to take a district. We turn it red, then out of nowhere, a blue Zerg comes and takes the only red district. I wonder why but I just stick to the shadows and stalk them hoping they move on to another yellow district so I can get in between an ad vs DC fight. That doesn't happen, they run into another district overrun with yellows, but completely ignore them then disappear into the sewers. Then the only blue district becomes yellow like 10 minutes later and no one bats an eye.
The green alliance is evident topside but it created more fun for reds, but it's not as fun in the IC.