The AI definitely needs some improvements, but that hardly will be a core feature of a future DLC. I think Firaxis is trying really hard to make it as good as possible with every patch. Still not good enough, though... But making some changes to the combat system itself? That could be interesting, but at this moment I cannot imagine how it would work. Larger armies being your main point: What can we do to go beyond corps and armies? Additional levels (4 units, 5 units...)? That could be starting to be very powerfull and I think we would notice that it would require the units to loose some of the "stars" with damage. Because otherwise it would be not really fair - you combine 10 units to create a powerfull huge army and no matter what you do, no matter how big damage you receive, you can still easily heal the unit to full 10-unit strength? But if you start loosing the "size points" of the unit with damage, aren't we simply back to stacks of doom? Aren't we going away from the 1UPT? I think the current system is great and needs just better AI.