It's possible that those arrowheads were inserted into a slot below the harpoon tip, looking similar to thorns on a rose stem, but I don't think they were in this case. I think they are individual arrowheads or harpoon tips. They are about an inch long.
I tried looking up the location of the village but my search led to two different locations. However, I don't think the village is near the ocean, so there probably would not be a need for a large harpoon with several blades attached.