As someone who followed the development of Bannerlord since the first blog post and who first played Warband in 2010, I can confirm that it is truly excellent and with a handful of mods is straight up better in every way but one: in Warband, the total conversion mods are fully mature entire alternate campaigns. I must've sunk 100 hours into Gekokujo (Warband mod that puts the campaign in warring-states era Japan) alone, let alone A Clash of Kings (the Game of Thrones total conversion).