And indeed, this was the common practice at the time. Hardly to be seen as an alternative to non existant standing armies. It is just how things were done.

This is just projection. People had always struggled to limit authority and in the English speaking world, this officially begins with Magna Carta.

What the Constitution does prohibit is billiting, which frames this discussion in a different light.

Maybe. But there was no provision for a standing army in the Articles of Confederation and no precedent for one. Standing armies weren't even a thing throughout the middle ages. Rather armies would be "called up" as needed, from the general population.This was the case in the English Civil War, and in the many American wars with native people, and indeed with the American Revolution. Hard to say people distrusted a thing that had not existed for 2000 years.

I did not know that 1.2 million black men served in the army during ww2.

I never realized that German army's had a separate army for African Americans and White Americans.