Even the Iranian people seem to be of the same genetic background as the Arabs ~ but they speak Indo European languages due to some obscure pre-historic ancient conquest
Wrong again!!!!
Genetic testing shows Iranians to be genetically similar to other Indo-europeans, and less with neighboring Arabs
You'll need to provide a URL for that one. Last report I read was in Science News and it reported that the general, run of the mill, ordinary people in Iran were essentially the same as the Arab speaking people in immediately adjacent Iraq.
It would be difficult to believe genetic separation in that area could be maintained over the 6,000 or so years civilization has been extant there. Just the common trade in brides for cows would have mixed them up.