Most tribes survive by hunting animals and making use of their entire bodies, as well as foraging for additional resources and knapping rocks to make tools and weapons.Most tribes survive by killing other tribes. Most of them aren't peaceful, they're just doing what they think is best for the survival of their tribe.
The sword definitely made things easier to go to shit and escalated stuff though. It's the same with the Cold War and nuclear weapons, yeah there would be conflict between people regardless, but introducing something to the playing field that is solely dedicated to killing other people and making it easier to kill and injure other people does have a meaningful effect on the conflict and issues and interactions.In many ways, this was inevitable even if a sword wasn't brought and Thorfinn knows this. That's why he so quickly folded when the tribes made it clear that the settlers were no longer welcome. Ultimately, Vinland wasn't the land of peace that he hoped for. Even if he didn't come as a warmongering conqueror, his arrival brought change that displaced the natives.
He actually didn't want war. There was a whole scene about that.He wanted war.
He got war.
Mission achieved Ivar, well done.