@shylarahVikings' diet was the best at the time, they had meat, fish, vegetables and they were genetically bulkier and taller than anyone, that's science right there. They were proficient blacksmiths and really good hunters, so their skills with bows and other throwable weaponry was above average. Not only that but their shields were perfect at stopping arrows and slashes, with really hard wood covered by sturdy leather AKA That shit wouldn't break down easily. And even then, their armor was like the Knight's: Chainmail, helmets, leather inside of the chainmail, etc, etc.
And apart from that, if you think that "Oh but Vikings valhalla they don't wear armor cuz of death and glory and destiny" Yeah, no. Most of them did wear very, very sturdy armor as I said before. Also, "Glíma" has survived since 900ish or something like that, while martial arts in japan like Judo or Karate only started to become famous in 1900 or 1850ish. Overall, the vikings were bulkier due to their genetic information, with more stamina and energy because of the diet (Which, in Japan was merely rice and fish mostly) and they were experienced with hard work, most of them becoming fishermen/farmers/mercenaries for other countries.
An average Viking would beat an average Japanese soldier, and an Elite Viking like a housecarl/huskarl would have a tougher time fighting agaisnt a samurai, but ultimately win. It also depends in the fighters and whatnot, but in general, yeah, vikings ftw bby.
ALSO I KNOW WW2 USES GUNS I JUST MENTIONED GLÍMA BECAUSE I LOVE NORDIC CULTURE
