Why do people in the movie Rifkin wear horn helmets?

In the17th century, some Danish scholars imagined that their pirate ancestors were savage marauders. They wore horn helmets, skins, stout bodies, long hair and broken axes. But it turned out that this image was wrong. On the contrary, the civilization of the ancient Vikings was much more advanced than that of the British nation, so they could invade and colonize Britain for a long time and even occupy Normandy. Vikings were pirates and merchants. They are excellent sailors and brave soldiers. They are not only marauders, but also creators and disseminators of culture. In the mid-8th century, Viking colonies were everywhere in Britain. They generally live in some fortress-like settlements, use the shape of ships for reference to make roofs, build houses and halls, and there are uniform villages and towns within the tall log walls. They also pay great attention to appearance and hygiene, and clean themselves every week. Trim hair and beard. Viking warriors are well equipped. They usually wear nose helmets, eye masks and polished chain mail. The main weapons are a sword, a tomahawk, a spear and a solid wooden shield. The Nordic rulers did not bind them ideologically, so it is very important that they are very open-minded. They sailed to America, clashed with the local aborigines, left some traces and left.