longsword vs. the shield
Speaking of one of my problems with their "research...."
THAT WAS NOT A LONGSWORD!!!!!The longsword dates to the VERY late-12th century at the earliest. Blade is typically 36-42 inches long with a hilt designed for two hands. 99% of the fighting style is for TWO HANDS. Some longswords were light enough to use one-handed with a shield, but this was NOT COMMON.
The "Viking" sword was a transition between the Migration-period sword and the classic arming sword, with blades rarely more than 30" long, typically with parallel edges (until very late in the Viking period when you started to get more taper) of high-quality steel welded to a core of pattern-welded iron (beautiful swords, btw).
Also, that was a REALLY poor-quality shield. A Germanic warrior who could afford both mail AND a sword (that was prohibitively expensive at the time, this guy would have been a PRO) would probably have a shield made of several layers (I think they used 3-5) of wood. The planks of each layer would have been laid crosswise (so layer one up and down, layer two left to right, etc) and the whole thing would have been both backed and faced with linen (the shield in the episode was bare wood). In addition to the iron boss there would have been straps of iron across the face to help hold the planks together (as on the TV shield). The shield would have more often been edged with leather. The leather rim would have been soaked in water then allowed to shrink tight around the shield, which helped hold the whole thing together. Tests performed on a shield made in this fashion was EXTREMELY durable, to the point that even if the planks WERE broken or shattered, the linen facing and backing and the leather rim would hold the whole thing together and keep it usable for the duration of the engagement.
Oh, and Vikings wouldn't have thrown both spears at the same time like that. I don't know WHERE the hell they got THAT idea. I've been in communication with someone who actually re-enacts Viking age warfare as research for a project I'm working on and who's written a couple books and even built a late-Viking age (c. 1000 CE) Anglo-Saxon mead hall. Based on conversations I've had with him (unrelated, but applicable) what that Viking would have done was to approach that Samurai with his shield raised to defend against the arrows. He'd have one spear ready while the other was gripped in his shield hand. As he moved in to range he'd throw his first spear, then take the second and throw that one (actually, he could have three or four MORE spears at hand altogether). Depending on how he approaches the fight, he might decide to hold on to the last spear and use it hand-to-hand (contrary to popular impression, the SPEAR was the primary weapon of the shield wall) to take advantage of the greater reach while still maintaining the defense of his shield. Either way, I would have pressed in on the attack to deny the Samurai room to use either his Naginata or Kanabo (big weapons need room to swing. Push in, you take away his room and leverage). The added advantage of the spear is that as a thrusting weapon:
1) It's a lot more maneuverable at extremely close quarters
2) There's a good chance of penetrating a gap in the armor
And saying the Samurai were more skilled is the perpetuation of a myth that is exasperating at best (someone in our fencing class visited a Kendo class where the instructor said something to the effect that Western martial arts were nothing but clumsy hacking. She shut him up REALLY quick
). Weapons do NOT exist in a culture in the absence of an art to USE them. Your reference to I.33 (I've only learned small bits of it, as I focus more on the longsword--which btw, longsword has many cuts and guards similar to those used with the katana) is actually rather close to reality, as I.33 probably in part evolved from sword and round shield combat. However I.33 is designed for sword and buckler so while some techniques would have been applicable there's quite a bit that wouldn't have worked with a full-sized shield. A Viking warrior who could afford mail and a sword was a PROFESSIONAL--for that matter, the "Peasants with Pitchforks" imagery of Medieval warfare is horrendously flawed at best (the Germanic cultures of Northern Europe/Scandanavia and England had some of the BEST PROFESSIONAL INFANTRIES IN THE WORLD. There's a reason the Varangian Guard was legendary). He would have known EXACTLY how to use that equipment with just as much subtlety as the "nimbler" Samurai.