Adding France and UK to EF country list?

[Crossroads]

I was thinking adding France and England to EF country roster, mainly to try my hands at a couple of what-if Winter War scenarios where Finland actually would have made the official request for help, and the Anglo-French Expedition actually would have arrived to Finland, instead of just occupying Narvik port in Norway and Swedish ore mines just over the border as the offer for help was interpreted by the more suspicious minds of the time.

Are there available slots? Would it be easy to achieve this?

Adding these countries to EF could be an addition to my Lapland War Mod. I would only consider it though if there would be available slots, so that the LWM would remain backwards compatible.

Regards Petri