[mantas]

Modern Sweden was only a part of origins of vikings. If it is known that those people are specifically Swedish vikings, then it makes sense to highlight that.

[fmbb]

It actually makes very little sense to “highlight” that in the context above.

It would perhaps have been interesting to point out that that region of Sweden is called Roslagen today, and has been since those times.

[mantas]

If there are even more historical details known… The more precise it is, the better.