The best that I can think of saying here is that it's a game. Real life differences between societies have to be put aside for simpler, more generic gameplay rules that work and can be understood. History is a big part of the attraction in Paradox games but in the end you're playing a strategy game. People like to win and conquer the world, that's what most strategy games (and games in general) are about. Of course there is that old school hardcore crowd who like the bittersweetness Paradox games offer, and feel CK2 is too much on the sweet side. I'm sure you can find what you look for in the mod section. Don't get stuck on the naming and classification of things, use your imagination. If you think the only rightful Empire is the HRE, see others as regular kings with viceroys. If a certain kingdom shouldn't exist, think of it as a big duchy or grand-duchy.
