Team Game?

[Rabbit]

I wouldn't say choosing a scenario based on an easy split of forces is not relevant, as I think it improves playability because you wouldn't risk having one player end up with a paltry sized force to control and it helps players from stepping all over each other's toes by accident. However I understand why you might prefer a more random assignment of forces, so it might just come down to personal preference and there certainly is no reason you couldn't play a scenario in the manner you described. Also there is no reason players on one side can't hand off control of units on the fly to one another.