How did you get Swedish, French, and Prussian decisions in HT? Didn't they stop the ability to convert between or out of cultural union nations?
Started the game as Sweden then took over Brandenburg and the saxon lands and then sold my Swedish possessions to Norway, and made my primary culture Saxon.
There's no French decisions there though, the +12% discipline modifiers are from advisors (I think I may have had an advisor born in France so that might be where the confusion is).