At Culloden many would probably have been barefoot...but beyond that the buckle shoe was the man's shoe throughout the most of the 18th century and well into the 19th century.

Paintings of highland men made during or around that time (1740-1830) invariably show a buckle shoe. Paintings of Englishmen, paintings of American men, even Frenchmen, depict the buckle shoe or boots...with almost no other option--I can't think of one offhand.

And a nice black buckle shoe is as appropriate today and as formal/dressy with a kilt as anything out there...although I think the Mary Janes looks a little silly, esp. by comparison, but that's just my personal (professional?) opinion..