I would have to disagree with you, Alf. I have seen the side with the lower numbers reset the map. Not often, granted, but I've seen it a few times. That is cooperation and teamwork.
Having double the numbers and just steamrolling everyone, not through cooperation or planning, or multi squad raids, but just by having the biggest horde isn't really my idea of a behavior that should be rewarded, and that's mostly what I see anymore.
To paraphrase HT, Games are meant to be fun and fair; war is meant to be neither. This isn't war, this is a game, and all the other paying customers should be able to have some fun, too. A horde is a horde, but not having to face strictly late war planes does help in that respect.