What are the Cheats on H Campaign?

When I play VH campaign, it is obvious that the AI cheats with extra money. However, on H it is not obvious to me. I see that the AI is more aggressive and less accomodating, but I cannot see what the cheats are. Are there any, and if so, what are they and how can they be verified?

Well in RTW the AI on Hard would get a bit of extra money and a few minor bonuses on the battlemap (I believe). Whereas on VH the AI gets almost unlimited funds and some pretty hefty battlefield bonuses.

In BI I am not sure...