This was an interesting reading, I must admit it, but with regards of the idea for DLC, we have to remember both expansión for Warband introduce new mechanics, such as gunpower (Canon, muskets, mortars, etc) and destructibles buildings in Napoleonics War and new features for Viking Conquest, such as naval Battle (on sea and on harbours), base for player, religion, history Mode, etc.
Many of those features would be desire it for Bannerlord by the community and yet, as everyone know, we dont have it. Personally, i dont want those features being in DLC, I want them in the base game (except gunpower, those dont belong for the timeline) but, if there should be implemented back as DLC, what else that doing it with a new timeline that fit those features (Seven years War for gunpower and naval as MP dlc and maybe other historical place for SP campaign like Oriente warfare with the infamous Elephant DLC)
TLDR; great history lesson, it fits better with a mod rather a DLC.