The Hoplites are the sinews that connect the muscles of the Kalshodar to the fist of the Empyraeum so the saying goes.
During the time when the bloodless conquest was still in progress, the regular army was known jokingly as the "irregular regulars". Regular humans, unchanged by Dragon but made up of one hundred different nations and classes of soldier; Macedonian and Greek spearmen, Persian Immortals and infantry, Scythian horse archers, Xin sword and spearmen, mysterious monks of the mountains...the army was the Empyraeum to come.
As Alexander had been heard to say "The Kalshodar will take the empire but the irregular will keep it." He wanted no police or military state where mortal citizens had no stake or involvement in the safety of their homes and families. He wanted no bee hive with the soldiers and workers determined at birth, doomed to monotonous eternity. He wanted no terrified slaves.
So each member nation and, later, each human occupied world, could and would raise its own regiments. They would be well equipped, well armed, and well trained in the defence of their home territory and, in times of great need, of the Empyraeum itself. They would be a police force in times of peace and of assistance at times of disaster.
They would wear both the colours of the Empyraeum and their nation with pride.
They form garrisons and response forces, help crew and secure naval vessels and take part in mass actions when required.
When the Kalshodar cruisers took to the stars on their long journey, each carried army divisions with them to police the crew and ancillary population. As that population changed, so did the occupants of the uniforms and, though it was never official policy for positions to become hereditary, it is not unknown.
On the hidden base under the surface of the moon, those trained to crew the Dragon's Crown before its disappearance, veterans of the Union War, made this a practise of necessity when even the Kalshodar were not to be informed of their presence under the moon. Though some were later recruited from the home planet, most remain lunar born with the great height and spareness of frame growing up in a low gravity environment gifted to them
All fit boys and girls were trained from an early age so that they would be ready to march beside Alexander on his return and retake their home.