As a suggestion, could you add unit specific banners for the Blood Knights of the Vampire Counts, as you did for the Empire and the High Elves? Here are some pictures as an example:
https://images.dakkadakka.com/gallery/2020/3/9/1048783-Blood%20Knights,%20Vampire%20Counts,%20Warhammer%20Fantasy.JPG
https://ageofsigmar.lexicanum.com/mediawiki/images/c/c8/Blood_Knight_M02.jpg
https://ageofsigmar.lexicanum.com/mediawiki/images/4/4b/Blood_Knight_M01.jpg
https://www.picclickimg.com/d/l400/pict/223529930639_/Blood-Knights-for-Vampire-Counts-of-Age-of.jpg
And is it possible to make a dismounted version of the Blood Knights to give them a high tier melee unit? I know its not in the lore but it would give them a good unit for the late game.
Additional, what about region-specific units for the vampire counts? I was thinking of the Drakenhof Templars and Drakenhof Guard. Only recruitable from the drakenhof-court building chain.
And maybe the Knights of the Red Death as a Regiment of Renown of the Blood Knights. Here are a few sources of inspiration, a few mods already exist for these units:
https://us.v-cdn.net/5022456/uploads/editor/1g/mhx86i9rrvde.png
https://us.v-cdn.net/5022456/uploads/editor/zp/xzq9o9p08mgf.png
https://us.v-cdn.net/5022456/uploads/editor/ei/vu3njwlxrg37.png
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=1183554889
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2265419320

Maybe I can add the banners later, after I'm done with Southern Realms. I probably won't add RoR, since I done none for any faction yet. At least not for game 2, and for game 3 it will only be after a long time, porting the mod and adding game3 factions wll take months

Besides the RoR and Banner, what do you think about the other things?

Very unlikely for game 2. Maybe game 3. Depends when is the actual release date