Thanks for the link.
I did see this video, and actually, that's exactly what I was doing (trigger on any event to change the houses at startup) however, there're few issues with this approach:
There's no AI in the house assign list (at least none that I can find). This means the AI houses must be known beforehand (and fixed) in the map. Obviously that means you'll always have to play against AI opponents that match the map triggers.
Also that limits who can ally with who. I can't for example have 2 teams of mixed human/AI players unless the map triggers are pre-setup for such arrangement.
For the time being, I resorted to assign all civilian structures to a single house using triggers (e.g., Korea), and made sure the AI players all allied in one team and at least one of them is Korea. The human players were all allied in another team. That worked, except none of the AI players attacked human players for some reason. They defended their bases but never ventured out of their base area (the civilian structures, now Korean, shot only at human players)
Instead of using triggers, I tried to assign the civilian structures to Korea, but it seems if I set the owner of any structure to any house other than civilian, the structure doesn't show up during play.
So I'm at back square one. I tried looking at other maps that has this feature but I don't see any triggers attached to the civilian structures. I don't mind editing the "ini" file but the help on both ini file editing and FA2 is scarce at best.
Cheers