Or, they could be a type of anti cav trap. Now think about it, a couple of throwers lace a forest with these bad boys and bait cav or charge them, they get out of the way and BAM, horse hits one of the trapped trees and takes damage! Or a wall covered in these "throwing daggers", now it becomes a spiked wall of "fuck you horses!" It would give low lvl players/new players a neat way to effect the battle, and make it so horses cant just charge with no danger!