Numerus- who was counted?

[Jugibar]

You have misread Hyginus.

It was a cross-reference from Roth. But, as you said, the point stands that the 600 includes 120 non-combatants, which is why he used the term homines.

In comparison, it would be interesting to see whether any of the Latin authors use milites or homines when describing the composition of the legion.