That would depend on the willingness of the Dalsnesers to listen to a Dane for long enough to learn something worthwhile. Or that he survived the rash in Norway and not on Bornholm.
Oh! Uh... yes, sure. (Acting as if I hadn't forgotten the geographical and cultural gaps.)
Shall we assume the Danes prefer Humongous Mecha, the Swedes are too pompous to adopt any non-native techniques, and the Icelanders don't have any large land predators? And the Norwegians are open to any super-awesome killing technique, no matter who presents it? (And how much he mumbles?)
Actually, the Finns, with their forests and ancient traditions of silent tracking/warfare, would probably appreciate Ninja Archery too. Don't know about the rollerblades, though...