But those are the fundamental questions, right? Are the Palcic clusters (good word choice) all related at some more or less distant level? Are the old country ones also related, historical and modern international borders notwithstanding?
There are any number of mechanisms, not least of which are army movements, to account for DNA distribution,you are quite right.
As for the science of DNA, well, for me, I think that I'd just as soon believe some disinterested lab tech as a very interested recorder in, say, a family Bible as to who great, great, great grandaddy maybe was! After all, Europe has been run by a lot of families for a long time who trace lineages ever so reliably to people like Aeneas... Cyndy