This was the conclusion by the scholars/scientists/genetics that tested these people. It was not a guess.
The guess is what everyone writes here, you and me included.
maciano basically did a summary on what these genetic people documented.
Stop dribbling this bull-shit nationalistic crap taught to you by some story teller or friends at a card game or drinking session.
this is fact, every nation LIES about their own history, its a way to keep the nation intact. Lies on lies on lies. DNA cannot lie.