I should think that all gets diluted even more today. I am very definitely English, I am back to the 18th century with my family history, but I don't come from anywhere in particular. I have moved around a lot, my parents moved around a lot and my grandparents moved from their place of birth- even my 4x great grandparents moved. I live in a town where you are far more likely to meet 'incomers' than those born and bred here. I would think it was all to the good that we were so mixed.