Did you figure out how many cards per turn it plays at with different game sizes?
I dont know, if you know the Command&Colors "Battlecry" rules, but the number of cards in hand (and maybe the numbers of cards, which every player may play per turn) can vary from scenario and also from each side.
So in my Champion Hill example, the exact number of cards can determined only after i have all units and setup ready and played test games.
Look at my "Antietam Cornfield" scenario, which i did for Battlecry, this example show you, that the scenario rules can decide, not only the number of cards in hand.
And also this scenario was tested at least 10 times, before i determined the final rules.