What's the problem?
Dont you guys know history?
Wars are not fair.
If i have a strong enemy and a weak enemy, of course i will prefer to ally the strong one, because i don't want to lose.
Hitler allied the japanese because they were strong.
When france surrended in ww2, the UK was basically alone in europe, but they fortunately won.
I know this is a game, but it's a war game.
And yes, i'm a Allyfag(only do that with my brazilian mates, because they rarely betray me)