The Assyrians, yes, but the Persians incorporated all subjects into their armies. Herodotus describes the composition of the Persian invading force in great detail, information he got from the Persians themselves. The Asian Greeks served the Persians, and worked as mercenaries for Egyptian pharaohs. The Babylonians relied on their Scythian and Median allies to sack Nineveh and smash the Assyrian empire.
Yes.
But the Persians never actually incorporated non-Persians into the actual Persian army proper. The army which Darius led into Greece was actually an assemblage of different military forces recruited from various subject people who fought in their own weapons and style. The Romans did this also with Auxiliary forces. But, as in the case of the Alaudae, one of the earliest examples, they recruited into the Roman Army proper individuals of non-Roman blood and armed and trained them as Roman soldiers proper.
The Romans did so with non-Roman and non-Italic people to an increasing extent with time so that the Roman Army proper towards the end of the Empire was nearly entirely composed of people recruited from outside the Italian Peninsula.
Even the auxiliaries were officered by Roman soldiers, learned Latin, and when discharged received full Roman citizenship. An inclusiveness absent in other Ancient Empires.
I believe the Romans practiced a form of incorporation and assimilation of subject peoples into their power structure to a far greater extent than any political entity before them and any of the political entities which existed after them for some time.
And that, I believe, is one of the reasons for the strength and stability of the Empire.