I was on my way here to comment also. I guess, arguing with a bot makes no sense but my original post is outdated. With the updates it might well be that medium is easy for experienced strategy players. There are some material in the forums regarding the challenges with trying to balance the AI if you are interested in the reason for why it was soo hard.
I just completed the House of Harkonnen campaign with standard settings (medium AI). The fifth map was brutal. It gets much easier after that map. Facing siege tanks without having your own makes this map a challenge. I saw some videos online but they must have been playing on easy. The trick I ended up using was to wait for all the spice to be harvested with me having stored a large portion of it. Then I kept the engagements efficient and waited for the AI to run out of credits. Specifics: I started...