Well, you know i am favorable of this theory as well Riverman, i just want to look options, but Vatin at least partially is my other option as well, because nothing is too conclusive yet.
You know, we need a big punch for the LBA-EIA, that's just Vatin, it was rather going KO, to put it that way. But like so often, it could be that the descendant culture overruled the parent one, kind of. That's something I also don't really believe, but its something I wouldn't exclude completely.
But like Oraku was pointing out, we rather have to look East/North East.