The Pheon Peons?
I forget when it was, but I was in a heraldry group with somebody I'm somewhat distantly related to, and we got into a discussion about the symbols on his family coat of arms. They are called pheons and they are arrowheads as they were in the Middle Ages. Because of this being so definitive a weapon of war, the pheon has been a frequent symbol in military insignia, and it led me to look for insignia like these for one of my wargaming armies, in the interest of setting their character traits.
The two images above are courtesy of the Pentagon's Institute of Heraldry. The units are the 128th Aviation Brigade and the 158th Infantry Brigade of the U.S. Army. They are both training formations in the Deep South of the U.S. (Fort Rucker and Camp Shelby, respectively).