[Tollund]

Of course it would be possible. Just create a nation where the AI can recruit juggernauts as troops and vampire lords as commanders for 1 gold and 1 resource each. It would easily crush any human player then, but still wouldn't be a very interesting opponent.

Anyways, you're still conflating the AI with nation/pretender design. The AI is the decision making engine. It cannot be modified, changed, or affected in any way by the players. One can create better pretenders and cheat in other ways for the AI, but this is _not_ AI modding.