Modding Query: How to Randomise AI Room Types?

[Miles Invictus]

In the title lads. I'm currently making a mod to use custom backgrounds for AI Empires in Diplomacy (instead of the room, window and city backdrop).

Take the Aquatic Species for example: I've managed to make it so that one room works for them - when entering diplomacy with an Aquatic Species, they use my mod specific room. So far so good.

However I ideally want to cycle between various rooms instead of be stuck with the one same room for all aquatic empires; e.g. "I click one aquatic empire in diplomacy - it has background #1, while aquatic empire 2 has background #2 etc.

How would I make this possible for my mod?

I've tried making the following in the room_textures file (asset_selectors);

Spoiler

"aquatics_room" = {
exists = owner
owner = {
NOT = { is_country_type = primitive }
is_fallen_empire = no
aquatics_portrait = yes }
room = aq1_room
OR = {
exists = owner
owner = {
NOT = { is_country_type = primitive }
is_fallen_empire = no
aquatics_portrait = yes }
room = aq2_room}
}

Any tips guys?