Why did the Nederlands, Switzerland, Bade-Wurtemberg, Bavaria and the Kingdom of Italy aren't protectorates of France, but only allies ?

It would be more historically accurate, maybe there is gameplay necessity ?


Is there a possibility to put theses states as protectorates for the campaign of 1805 and 1807 (also with the Kingdom of Napoli for this date) ?
Maybe with a modification of some files, someone could help me please ?