Under the system of the Taira family, the person who led an area army had to be somebody in the Taira family (a son of Kiyomori or his grandson), and it can be said that those who actually commanded the army were the highest rank of gokenin in the Taira family.
平家のシステム上、方面軍を率いるのは平家の一門(清盛の子及び孫)と決まっており、その下で実戦指揮を執るのが平家の御家人の最高位といえる。