One suggestion to keep improving the complexity and challenge of our maps is to possibly include territorial advantages.
I don't know how feasible this would be on the programming end, but it would be very cool if holding certain territories in the mountains offered that player an attacking and defending advantage (but perhaps a fortifying disadvantage).
For example, I was thinking that if one holds, say, Nepal in the Asia map, they would be afforded a the regular number of dice +1 (so attacking 5-1, they would get 4 dice! and defending 7-2 they would get 3 dice).
As well, in a one-fortification game, perhaps the territory can only be fortified by a maximum of one half of the armies in the adjacent territory with the largest force.