The 2 country idea will always fail due uneven numbers issue. There would always be one side clearly dominating the other in numbers as opposed to the two countrys we have dominating the knights in numbers.
And why do you believe that?
Is the issue that people only want to play on the 'winning side'?
If so wouldn't a mechanism to prevent them from switching the numerically advantaged side be advantageous?
Or is the 'freedom' of choosing a side more important than having good game play?
It breaks down into to groups...
1) people who believe everyone but the muppets and a few others would be on one country...
2) people who believe that high eny and clouds of green will encourage people to switch...
And there are two approaches...
1) enable people to freely switch with no penalty.
2) penalize people who switch to encourage stability.
I don't see a way for having 'freedom' and believing in group 1, and with that said it goes back to, is your cartoon "freedom" more important than your desire for good cartoon gameplay?