Is the AI Constantly funded?
Also, if they are using Supply Docks. Then some daring players would try to steal from them...
The whole concept of starting with a lot of cash without any means of recovering lost funds... Except maybe Supply Drop Zones, Hackers or Black Markets.
Is kinda odd and somewhat the challenge is stacked against the player, but I digress becase, someone here did beat 7 hard AIs on their own.
One thing you need to do is to keep the AI Constantly Funded. Lets say it gains 1000 credits every 5 minutes.
Make it so that they rebuild all necessary buildings especially Command Centers.
Death Label:
Reduced back to 3 main factions(and a couple of extras).
Each faction can choose a(or all of them) tech-tree via General's Powers.
Angel Wings: Jets and Anti-Air, Helicopters and Missiles, Hovercraft and Lasers
Red Skulls: Armor Division, Mecha Armada, Drone Swarm
Earth's Saviors: Air Raid, Homeworld Security, Stealth