The Variags/Varangians were instumental in uniting the tribes and organizing the state. But those involved in active ruling got quickly assimilated.
What is probably significant for our discussion, is that the Varangians have not been under full influence of Christianity by that time. Their state building was independent of the Romans as well. When the Vikings became more "mainstream" Europeans, they were not influencing Russia anymore. So your point only underscores some distinctions - though I can't say anything definite how important (or not) that was.
