I am very much in favour of territorial distinctiveness. I found a surprising essay where John Stuart Mill forcefully attacks it.
“Experience proves that it is possible for one nationality to merge and be absorbed in another: and when it was originally an inferior and more backward portion of the human race, the absorption is greatly to its advantage. Nobody can suppose that it is not more beneficial to a Breton, or a Basque of French Navarre, to be brought into the current of the ideas and feelings of a highly civilised and cultivated people — to be a member of the French nationality, admitted on equal terms to all the privileges of French citizenship, sharing the advantages of French protection and the dignity and prestige of French power — than to sulk on his own rocks, the half-savage relic of past times, revolving in his own little mental orbit, without participation or interest in the general movement of the world. The same remark applies to the Welshman or the Scottish Highlander, as members of the British nation.” (Mill 1861: 294-5).
We have come a long way since 1861. Let us do not fall in the same evolutionist trap when thinking about Scotland and other small nations today.