Back in the day there was mod that replace characters portraits with Dynasty Warriors 9 characters and added some characters as well. Sadly it died at version 1.2 (let me know if you can roll back your game to that version if you find a way.)
But PTYHHS the mad lad went through the effort of making the base version of it work again, sadly we lost the new characters but we got Dynasty Warriors 9 characters back.

If you want to see it for yourself the set you game's version to 1.5.3 in the beta section after right clicking the game on steam. Then download the the mod and use the Vortex menu from Nexus.

I hope people who wanted to check out have the opptunity to and perhaps someone can add some additional characters to the game. Like Dong Bai and Lu Lingqi

Here is the original mod on Nexus: https://www.nexusmods.com/totalwarthreekingdoms
PTYHHS Posted the mod.

PTYHHS
For people begging for an update, I've gone through and fixed it for the most recent patch (6/30/2020)

All it was was tediously changing file and folder structures and resizing images, then redoing metadata. It's a big file due to the way images had to be resized to fit the new portrait sizes, and all the pictures are included within the .pack file. This version is probably incompatible with the default total_war_dynasty_warriors_9_officers.pack as it merges that pack into the new one. If it doesn't load, make sure your user.scripts file inside appdata/roaming/the creative assembly/threekingdoms/scripts folder has the following lines inside:

mod total_war_dynasty_warriors_9_events.pack
mod total_war_dynasty_warriors_9_officers_fixed.pack

I haven't thoroughly tested this, as I'm still new to the game and I'm more familiar with STALKER modding, so there might be various bugs here and there, but it should be mostly functional. As a matter of course, if the main file is ever updated, I'll take this down, it's only here for those people looking for a fix.

https://drive.google...QdkXK7d6lV/view