We would best include weapons/armor from the Inuit, Beothuk, and Thule groups of native americans, since those were the tribes most probably in contact with the vikings of yore.
We actually DO have examples of the weapons and tools that these particular tribes used during pre-columbian times. That's how we know that the Thule did not use the bow and arrow, but mostly lance and spear to hunt on the ice. The Inuit did have the bow as well as other more advanced weapon technology, and that's how they drove the Thule from their place.
We could totally add a "flat bow" (american style bow), "self bow", "chert arrows", "bone lance" as well as different styles of fur robes and such to include these styles.
There's no reason not to! Except that someone has to make the models. If someone wants to make the models, I will write up a strong case for adding them.