An interesting channel regarding Viking sword and shield combat run by my friend (and I.33 studend) Daniele Imhoff. He is adding a number of plays to re-create a fighting system. Please notice that this kind of fighting style best suit a 1 vs 1 fight.

Here is the link of the channel

https://www.youtube.com/channel/UCrO_Gr2MqsCgB0Q9WQhlGrw

You can start from play number one by clicking on this video.