Great scenario - good to play CC on a new map.
The scenario being set in the future requires the contrivance where the planet has a high density/gravity limiting the use of lighter than air/ flying machines. Obviously this is required to explain away the absence of flying craft in a future scenario.
How difficult would it be to incorporate aircraft into CC? Aren't airborne forces not much more than a combination of the characteristics of both fleets and armies other than they can attack virtually anywhere?
If aircraft were to be ever brought into the game, I suggest that they would act in such a manner:
1. They can only attack the armies defending an an enemy territory and not the country, so they can't invade by themselves.
2. They would be unable to hold a country or defend or take a country by themselves
3. They can transport troops onto friendly territory, paratrooper-style attacks possible but only at very high cost to the attackers to reflect the costly reality of airborne assault.
4. They can transport troops into neutral territory to bolster neutral armies? - perhaps
Continued air attack might lead to a situation where no enemy armies were left to defend a territory. In this situation this might result in rebellion and a reversion to neutral status?