Playing as the Necromancer, the Orc Warlord, the Leader of the Wolf Pack, or the Goblin squad Commander in world of Battle Brothers would be fun in a way.
I think that would make a good material for Expansion or DLC, once the game is finished.. or even a Mod if BB will have extensive enough mod support, but i doubt anyone can pull through such a feat on the same quality level as Overhype Studios.