MacDonald, MacMillan, Douglas-Home, Blair, Brown, Cameron - all UK prime ministers during the last 100 years, all have Scottish origins (and names). Perhaps it's a class thing, that the upper and middle class Scots are outward-looking internationalists at heart and the working classes are more interested in the nationalism of Salmond.
Scotland's greatest export is Scots. For a small population, they have punched above their weight for several hundred years, which is a credit to their intellect and character and ambition. United fans will understand that better than anyone.