Isn't that just a fancy way to say they're from Old English (Anglo-Saxon/Englisc)? This shouldn't be too surprising considering the other main influence of the English language was Old French and the letter combination "sk" is far more common in Nordic languages than in French.
Effectively, there are three main sources for English:
* The Anglo-Saxons, arriving around the time where the Romans left.
* The Vikings, arriving around 800-1000.
* The Normans, arriving around 1066.
Not that English haven't changed significantly since then, but these three periods represent the largest number of words increases. The other changes have primarily been spelling.
It's why English nouns lost their masculine and feminine grammatical gender. The people who used both languages had more important things to worry about.
It all points to the case that English is actually a creole language.
Superstratum/substratum theory applies here. English has an Ingvaeonic superstratum and multiple substrata, from Old Norse and Norman French at least, if not more.
I had always chalked up the Viking invasions to "more of the same" after the Anglo-Saxons had settled, but you're of course right that the two (well, three, I guess) groups came from different geographical areas and the Vikings would of course have spoken a distinctly different language.
I guess I conflated the common view that English is originally a Germanic language with French influences with "English is Anglo-Saxon plus French over time".
It has later been "perverted" by the french ;)
However I do not think this theory would fly in England even if the logic is sound due to nationalistic pride.
https://www.sciencedaily.com/releases/2012/11/121127094111.h...
Scandinavian languages did not change due to this.
Read the article, they explain it much better than me ;)
Also, most linguists who are experts in the history of English (Faarlund is an expert on Norse, not English) tend to border on the dismissive when considering Faarlund's theory of English as Norse dialect.
I am fluent in Norwegian but moved to Norway as an adult from the UK and I still struggle with the words for shirt and skirt which are skjørt and skjorte, the sk is more of a sh sound, but the vowel in the middle I still cannot get right, those øs just don't fly with my accent.
Interestingly, in Scotland a lot more 'Norse' persists than in English with typical examples including kirk for church, pronounced shirk in Norwegian, and bairns for child much like barn in Norwegian. Other examples I can think of, not just in Scots but in English too, include tor for tower which is tårn in Scandiland (Google translate doesn't recognize tor as an English language word, even though it is used to describe towers all across the UK).
To my ear the snippets even sound like they're said in a Scottish accent and emphasizes that there's no such thing as a 'pure' language as they all have elements of others which have migrated in.
I would be interested to see if there was a correlation between the linguistic mix and the DNA origins of these populations - perhaps a cool hypothesis/experiment for someone.