Great Quiz! Baltic Empire should be Southern Baltic Empire, though, and I would remove West-Slavia because it is formable via a decision, unlike the others. Leaving it included would make it seem like others formed the same way(Roman Empire, India, Slavia, etc.) should be included.
both of those are not true, the game refer to the baltic empire as "the baltic empire" and is displayed as "baltic empire" and in none of the start date has it ever been referred to as southern baltic empire, while west slavia is formable through a decision, it can also be formed the regular way like francia and germania, so it should be included