Canuck in NI wrote: “And those ridiculous helmets, don't get me started.”

Well, as everybody ought to know, the ridiculous helmets with the enormous horns were a Wagnerian invention, not authentically Viking at all (whether Norse, Danish or Swedish).
And I found it interesting that it was a Buchanan who provided a long list of “Norman” clans – perhaps to emphasise that the Buchanans were not of that origin?
My recollection is that the name Buchanan was taken from lands granted to a son of a High King of Ireland by the King of Scots.
An authoritative history I read last year of Scotland during the Dark Age contends that the Douglases and others in Galloway were part of a wave of migration from Ireland that was distinct from the one that originally settled in Argyll, so establishing the (smaller and separate) Kingdom of Scots.
There is more than adequate proof that the Bruce (de Brus) family originated in Flanders – the name refers to Bruges or Bruggen. As I mentioned previously, Bruces were employed by William of Normandy to build and maintain a castle in his duchy.
And Sinclair is a name that did not appear in Scotland until after the suppression of the Knights Templar. No connection with William the Bastard at all.
Regards,
Mike