Having taken note of some AI discussions that have been ongoing in this thread recently, I figured I would dump my 2 cents of my impression of the "better" AI vs the AI of Vanilla BTS. This problem predates AND and goes way back ever since I started playing ROM so I am not sure its easily fixable.
The problem with betterAI resides in the battle decision making when an AI is at war. The underlying issue is that, unlike vanillaAI, betterAI is more focused on winning
battles, often at great loss, rather than
capturing cities. The problem with this, is that BetterAI, with its huge stacks, often times can be baited into attacking units with super high strength values in terrains with defense bonuses.
Example: If betterAI has 20 mailed knights (strength 14 each) in a stack, and happens to pass by 3
fortifiedriflemen (strength 26 with 25% vs mounted units) on a hill with hill defense promotions (25% defense bonus for hills an additional 25% defense for each promotion), betterAI will happily sacrifice most of its 20 knights just to take down those petty 3 riflemen.
VanillaAI would
never do this. Instead it would ignore the few super well defended units by walking past them. This is because it realized that it should focus on acquiring the closest city and that making a decision to attack the well defended units, although would result in a victory for that particular battle, would ultimately be too costly in the general war front due to the unit loss.
I have countless saves to back this up. In these saves the AI goes into a suicide run onto my well defended units on the very next turn. If need be I can upload them.
If this issue can be remedied, it would give the human player a lot more to fear from the AI on the war front
TLDR; BetterAI should focus on capturing cities rather than being baited into petty battles.