The action scenes feel weird
They are not realistic yet not stylized enough. They just feel... weak, like arms flailing around randomly while shouting like crazy.
shareI guess he was trying make an artsy action movie.
shareI noticed this too in Dune (2021). The fighting scenes in that movie looked even weaker. No energy at all, as if everyone lost their breath already.
I suspect it's because of how modern movie productions have ridiculously high safety requirements so anything actors do looked very careful movements, instead of, high energy explosive combat.
The Northman is especially weird tho' because had they gone for simpler, less flowerly fighting style, i.e., less movements, more stabbing, one slash kill, etc. it would fit better to the tone of the movie.
Real weapon fights look simple and straightforward because swords are incredibly dangerous. One slash and you're bleeding profusely. Downed on your knee means a certain death because nobody would wait you to get up, you'd get stabbed immediately. One chop and you might lose your forearm, which is also a certain death. It may look slow and not very exciting, but I think that should definitely work better for this movie with all the sombre vibes going on.
Instead they chose to do half-way. Not very straightforward, yet not very well choreographed either.