Last night, I played a 5v1 against normal AI's and stomped them quite nicely. This morning, I decided to see just how much easier it would be if those AI's were easies. The results were shocking: it was harder. Where the normal AI's didn't destroy a single building, the easy AI's pushed me back beyond my first line of towers before I got enough equipment to start a kill streak and own them.
The biggest difference I noticed was that the easy AI was more cautious. The normal AI is notorious for face-planting into a line of towers and giving first blood within the first 90 seconds of the game. The easy AI wouldn't do this; they only entered tower range when I wasn't around and otherwise wait defensively close to their own towerl ine. The easy AI would run up, spit on a tower, then run back. The normal AI would run up, spit on the tower, then try to attack me (within the tower's range...) and get killed in the process. The result was it took me a lot longer to get first blood to start my kill streak and rack up some good equipment.
When they hit my second tower line, they got a little more careless and got themselves killed, but I think that had more to do with the fact that it was later in the game. I was a higher level, I had better equipment (and plenty of proximity mines), and more citadel upgrades, plus my war rank had gone up and created extra towers to make the second line stronger (this was crucible by the way). Overall, I was actually impressed by the easy AI and I felt that in terms of behavior it was the most intelligent of all AI difficulties. There is a distinct irony here.