Source on Swedes being steppe barbarians? Most historians agree that Vikings originated in Scandinavia. Sami peoples originated in northern Russia and moved to the furthest north regions of Scandinavia. The Vikings were also more concerned with seafaring and raiding to the south and west and all the history I know of is that they coexisted mostly peacefully (Vikings would trade with the Sami). Conflict arose centuries after the Viking age.

https://en.wikipedia.org/wiki/Goths