This Christmas, while holidaying in Europe, I read Oppenheimer's 2006 book "The Origins of the British" which goes into much greater detail, hence this updated post. But first, let's remember that Alan Wilson and Baram Blackett have been doggedly researching the Two King Arthurs and the Ten Tribes of Israel for many a decade...
There's nothing wrong with research, if you have the evidence, but for me Wilson/Blackett's more important research concerns the runic writing known as the Coelbren Script, pronounced Coilbrin...
The Coelbren Script
Where does the Coelbren Script tie into Oppenheimer genetic research about the people of ancient Britain?
Any western migrating sea-faring or beach-combing nation of people who made it to Wales where their proto-Welsh ancient language-speakers might have also repopulated the western Atlantic coast of Europe several times since the Neolithic age. If so, maybe the Coelbren Script was written BY the Welsh-Basque Druids(?) and re-exported a millennia or so later via the Phoenecian shipping lanes as a Lingue-Europa or Unified Trading Language.
Maybe Coelbren was the pre-Christian era legal language of Western European trade deals and inter-marrying arangements among the Warring northern-european Redhairs and the Ambassadorial Brits. In my imagination, Boudica was the original Trophy Wife, imported for her battle skills along with her York-chariots... and sold to the resident Saxon-Frisian land owner of the Icenii tribe. Maybe this was how Europe was controlled, by the Druids(?), via the sale/transport of Northern Battle Wives through the eastern med to western britain.