You have to remember, a very very small band of Europeans with armor conquered everything in sight. To the point the Aztec leader offered him a room full of gold if he'd leave. The Spanish had no problems overawing the native tribes, neither would the vikings.
While the vikings may lose a man here & there to constant sniping arrow fire from concealment. Most tribes would simply evaporate into the forest and wait for them to leave. Like the Spanish, they were armored!
A bunch of guys in loincloths with primitive bows and stone hammers are going to go toe to toe with guys with chainmail, Helmets, shields, swords and war axes? Remember the natives had virtual no metal anything until they started trading with the white man.
So its stone arrow heads and hammers, a few 4" stone knives vs 3' swords and War Axes.
ROFLMAO
Sorry, no contest, vikings win.