It'll be interesting to see if Paradox is working on something more for the series. I remember CK2 first coming onto my radar because of its Game of Thrones mod, and you can find similar variations for Warcraft, Middle-Earth, Romance of the Three Kingdoms, and Harry Potter on CK2 mod sites. Crusader Kings 2 is arguably one of Paradox's most popular strategy games, likely due to both its focus on lineage and politics as much as military strategy and for its modding potential.