NCO-equivalents were also immensely important once it became apparent that low-mid level command could still be effectively exercised in the heat of battle. Roman centurions, for example, got paid 16x an enlisted man's salary by the time of the Early Empire precisely because it was recognized just how vital they were (and also because centurions took massive casualties and needed a bit of an inducement for anyone with a bit of brains in their skull to still want to stay in that front-line position)