I accidentally came across one MOD which adds Grudgebringers and all other SOTHR and DO regiments with characters to Warhammer TW campaign
You play as a nomad faction and you don't need to capture settlements to make money but taking on quests or random contracts. You can also raid and sack cities or capture them and give to the Karl Franz for some reward.
The MOD devs did very great job and I already had tons of fun playing it.
To play it you need to have WH2 (and WH1 for Mortal Empires campaign) and subscribe to these MODs:
https://steamcommunity.com/sharedfiles/filedetails/?id=2548096468
https://steamcommunity.com/sharedfiles/filedetails/?id=2299942334
https://steamcommunity.com/sharedfiles/filedetails/?id=1727923164
https://steamcommunity.com/sharedfiles/filedetails/?id=2156743064
https://steamcommunity.com/sharedfiles/filedetails/?id=2022286940
here you can check some gameplay videos:
https://youtu.be/-WwTIzNbQhE?t=1
https://www.youtube.com/watch?v=pLrippkKHyg
https://www.youtube.com/watch?v=fGfpuKT80SQ