I said it further down the post, but the legends may have been about the meteor metal, rather than the Hallows themselves?
Intriguing! Though that leads to the question of what happened to the rest of the meteor material. Surely the Hallows can't have been all that hit the ground? *resists doing calculations* On Earth, meteor craters are 20x the diameter of the impacting meteor. Something large enough to cause the ecosystem damage of the meteor that hit Haixing would probably be ~100m in diameter, or in any case much larger in mass than the four Hallows combined.