You miss the point. Referring to Napoleon as 'royal' (except as King of Italy) and 'royalist' are equally incorrect.

Not at all. Your point was clear but tangential.

'Monarchical' might perhaps have been more accurate, if one is disposed to quibble, but the qualifying term in Hans Karl Weiss' post, referring to NB's dynastic ambitions, made the meaning in his use of 'royalist' perfectly clear. As it is, HKW was referring to NB's ideas rather the man himself

Would it have been satisfactory if he had written 'imperialist' ?