I was doing a Skirmish against the Extreme AI on the Amazonia map. I was playing as Portuguese, while my opponent was British. As I’m much more familiar with Age of Empires II and have little knowledge about the correct build order, deck usage, or unit counters in Age III as of yet, I expected to be thrashed.
Instead, by the time the opponent sent military to my shore, I already had some warships and land units to destroy their raiding party without losing any buildings except a single outpost. Every subsequent attack they made went virtually nowhere, as I had already established solid control of the river with my Frigates and eventually Monitors and had added extra Outposts and land units for protection. I was able to keep booming until I got to the Imperial Age, while my enemy revolted. When I made my final push, my enemy was never able to wrest control of the water from me, and despite having a gigantic land army, she couldn’t get everyone over the river to sack my base. Even though my score was well behind my opponent for a majority of the game, I still ended up winning easily.
I tried playing another Skirmish later, this time on a primarily land map (California). The struggle was much more pronounced, as the enemy attacked me sooner and I couldn’t keep up with their unit production. So I’m guessing the Extreme AI, as it’s currently designed, was designed mostly to handle land maps. On maps that require Docks, it shouldn’t be nearly as easy to defeat as it was in my game!