Expanding the portrait generator

Hello everyone, I want to ask you some infos for a mod I was thinking to do.

I was wondering if it was possible to add new faces to the random character portrait generator without overwriting the default faces, so that each generic officer category has more chances to have officers looking different enough to recognize them.

From what I have seen the names of the CA assets all follow a schema that is something like <gender>_<officer_category>_face_xx, where xx is a number between 01 and 10. So I was wondering if using the same schema from 11 to n would made the generator know there are more faces to pick from or it is hard-coded. In the case this number is hard-coded, is it possible to modify it via mods?

Thank you so much in advance!

I'm working on a mod for Total War: Three Kingdoms where I want to change the portraits of some characters. While I managed to create new portrait images, they only show up in the campaign menu and revert to the default ones once I enter the game. Here's what I've done so far:

1. I created a new id_art for Liu Dai, named it 3k_main_liu_dai.
2. In campaign_character_arts_tables, I added a new row for my id_art and edited the portrait and card columns. The other columns were copied from cao_cao.
3. Then I went to character_generation_templates_tables, found liu_dai, and changed the art set override column to my new id_art.

Despite these steps, the in-game portraits still revert to the default ones. Am I missing any steps or doing something wrong? Any help or guidance would be greatly appreciated.
Thanks in advance!