Why 3?
Why do they use triangles in structures?
Why are there 3 branches of the US government (as opposed to 2, or 4)?
Because if one side gets outa whack, the other two together can rein it in.
Hypothetically, I mean. In this game seems the 2 most outta whack pile on top of the underdog, because most folks still don't realize the "win the war" conditions have changed.