Language can only take us back so far, and it is very difficult to track without corroborating evidence, which we just don't have for our period in that region. We only know that the slavic language group only appears in the AD period (can't recall the exact date). Before that we just have no evidence for that, and the evidence you put forward is no evidence at all. So we cannot make the claim on that area that would allow us to place a faction there. Nor can you.
Foot