I apologize for the lack of response on this thread. Been traversing across China so I've been largely away from the dev team.
Lach and Holps have been spearheading gathering information regarding this and I felt it merited an official response to what was changed in the AI in the last update.
Previously, when a troop/unit tried to target something from the side of the wall they were on, they would look at the 3 closest buildings to target. Now they consider 5. It’s important to note that being on one side of the wall is the key point. When a unit is on one side of a wall, we made the unit target selection consider more buildings and attack positions when determining the place to attack.
This is why it seems the AI has been functioning differently that before; it's because of this new targeting consideration.