Buffalo horns

The Buffalo horns formation is an a war formation in which the first two squads (the horns) attack and meet the enemy followed by the main bulk of the army (the head). Meanwhile, a small group of veteran fighters sit away from the battle (the loin) ready to come in for the clean sweep after the first squads are expended. (For more reading see https://en.wikipedia.org/wiki/Impi#Tactics )