2500 years, thats approx 100 generations so in order for these descendants to propagate they would've needed to be forced out of their territory every once in couple of generations(most likely invasions). Curious that it resembles the Dacian tribes population movement.
Couple of centuries of prosperous development(5-600 BC to 100 AD), at its peak extending in north into present-day Poland borders, in the south to the Roman borders pushing the romans hands(constantly ravaging their provinces south of Danube) and causing retaliation which led the romans to the discovery of the huge stacks of gold in the Carpathians mountains, making the SW region of Dacia a Roman province. This forced some of the Dacian population to flee in the North and East into todays Poland, Ukraine, Belarus and Russia where they were absorbed.
Then in the following centuries massive invasions from huns, goths, etc continued to attack the remaining Dacians from the East and North, meaning that again some of them were forced to flee but this time into west present-day Croatia, Bosnia, Albania, etc where they were absorbed by the local populations. The rest of surviving Dacians that used the mountains as a natural refugee from the invaders, were later assimilated with the Slavs people which continued to migrate in the south into todays Bulgaria, Macedonia, etc.
That one I2a-din ancestor could've been Dacian at origin, be lucky to live in the right time frame with a head-start of 7 centuries of prosperity to expand in a Dacian tribe until they started to crumble into pieces but its descendants were continually forced to migrate to north, east then west and south. Like the rest of the theories on this thread, no way to prove it but its sounds more valid to me than either Slavs or Goths origins that are based on external migratory routes which chronologically arrived to those areas much later.
Thoughts ?