- May 22, 2020
Having watched a huge Sid AI debug game with the C3X mod, a problem with these stacks is that they often end up with a bunch of defensive units and artillery type units and that's it. Once they find a city, they will bombard and bombard the city as much as possible. They will bombard to the city down to size 1 and destroy all improvements after redlining all units. That might sound ok, or might not sound ok. It's a tough call. But worse, is that no attacker ends up with such a stack apparently, unless it just so happens to come nearby. It's not like one medieval infantry or knight or longbow travels with such a stack. They will also park near a city and bombard it with no attack support for quite a few turns if the war continues.
I haven't seen how Korea handles their UU. I picked random civs, and they weren't in it. But, I would guess that Korea ends up with a military edge when warring against other AIs.
Edit: If an AI has infantry proper next to a heavily bombarded city, then they will attack.
I suspect the infantry proper doing the attacking you saw was not a unit assigned to guard the artillery but an offensively flagged one that happened to join.