Well, that's my take on the available evidence, but said evidence is pretty scanty. I wouldn't undertake to prove it. But I think it makes sense and, as I mentioned above, have made Extolay just such a world.If I recall correctly, aren't there many Imperial worlds in Deneb which are also Vargr worlds? I.E. There already were significant Vargr populations there, and the Imperium assimilated those systems as it pushed spinward?
Hans