Rather, this whole thread is a joke. A waste of the internet space. I could finish it very quickly, if I could post www links or insert images, but I need another eight posts.
In the meantime, you can think over the report of Konstantinos Porphyrogenitos (De Administrando Imperio, chapters 30-32), who relates about the origin of Croats and Serbs. Where do you think they came from?
(30)...But the Croats at that time were dwelling beyond Bavaria, where the Belocroats are now. From them split off a family of five brothers, Kloukas and Lobelos and Kosentzis and Mouchlo and Chrobatos, and two sisters, Touga and Bouga, who came with their folk to Dalmatia and found the Avars in possession of that land. After they had fought one another for some years, the Croats prevailed and killed some of the Avars and the remainder they compelled to be subject to them. And so from that time this land was possessed by the Croats, and there are still in Croatia some who are of Avar descent and are recognized as Avars. The rest of the Croats stayed over against Francia, and are now called Belocroats, that is, white Croats, and have their own prince. They are subject to Otto, the great king of Francia or Saxony, and are unbaptized, and intermarry and are friendly with the Turks.
(31)... The Croats who now live in the region of Dalmatia are descended from the unbaptized Croats, also called „white“, who live beyond Turkey (=Hungary) and next to Francia, and have for Slav neighbours the unbaptized Serbs... Those same Croats arrived to claim the protection of the emperor of the Romans Heraclius before the Serbs claimed the protection of the same emperor Heraclius, at that time when the Avars had fought and expelled from those parts the Romani whom the emperor Diocletian had brought from Rome and settled there, and who were therefore called „Romani“ from their having been translated from Rome to those countries, I mean, to those now called Croatia and Serbia. These same Romani having been expelled by the Avars in the days of this same emperor of the Romans Heraclius, their countries were made desolate. And so, by command of the emperor Heraclius these same Croats defeated and expelled the Avars from those parts, and by mandate of Heraclius, the emperor they settled down in that same territory of the Avars, where they now dwell.
(32) The Serbs are descended from the unbaptized Serbs, also called „white“, who live beyond Turkey (=Hungary) in a place called by them Boiki (Bohemia?), where their neighbours is Francia, as is also Great Croatia, the unbaptized, also called „white“. In this place,then, these Serbs aso originally dwelt. But when two brothers succeeded their father in the rule of Serbia, one of them, taking one half of the folk, claimed the protection of Heraclius, the emperor of the Romans, and the same emperor Heraclius received him and gave him a place in the province of Thessalonica to settle in, namely Serbia, which from that time acquired this demonination... Now, after some time these same Serbs decided to depart to their own homes, and the emperor sent them off. But when they had crossed the river Danube, they changed their minds and sent a request to the emperor Heraclius, through the military governor then holding Belgrade, that he would grant them other land to settle in. And since what is now Serbia and Pagania and the so-caled Zachlumi and Terbounia and the country of the Kanalites were under the dominion of the emperor of the Romans, and since these countries had been made desolate by the Avars (for they had expelled from those parts the Romani who now live in Dalmatia and Dyrrachium), therefore the emperor settled these same Serbs in these countries, and they were subject to the emperor of the Romans...
So much for the legends that Slavs brought I2a1a2-M423 to the Western Balkans. Yes, you read correctly: Serbs came from today's Eastern Germany (where their relatives live until now) and Croats originate from "White Croatia", which is placed to northeastern Bohemia and/or southern Poland. The Byzantine empire needed recruits because the Balkan provinces were recuperating from the consequences of the Justinianic plague (541-549 AD). The depopulated Balkan area was an easy target for Slavic raids starting after 550 AD, and then for the Avars (after 567). This is why Herakleios (ruled 610-641) was eager to accept Slavs in the Balkans. But we know that it did not pay in the long run, of course...