Well, I was thinking of Kyiv Rus, which appeared almost a thousand years later and were arguably Slavic people with a Scandinavian elite... but if you read the history in different languages around the region they once inhabited, you'll get quite a different picture. I don't know if there's something similar about the Goths, but I am just saying that the academy apparent preference for the Goths having been just a moving culture for the most part, with little population displacement, seems quite biased towards the very common "our people were here for eons" narrative, from the outside.