Rome had professional standing armies more than 2000 years ago.

You are absolutely right, my mistake. None-the-less, professional standing armies didn't exist in most locales for most of history.

Most locales for most of history couldn't afford standing armies.

And not even from a financial standpoint -- there simply wasn't enough excess goods or food to have them out of the workforce.

Yes, that's true. A war machine requires surplus value. One reason why feudalism developed in Europe was for mounted warriors to be able to supply their warhorses. Facing constant violence, only super-appropriation of peasant surplus could give local lords and warriors enough resources to hold their own. And much of the success of many of the empires of history lies in their ability to requisition surplus value and use it to hire enough military labor. Rome could muster more soldiers than Carthage, for example.

Many centuries passed during which there were no armies with the qualities that those of Rome shared with those of Napoleon.

I agree about the not wanting to die but "Not wanting to kill someone is something like a universal." is clearly wrong in a lot of cultures. And ignoring this fact is precisely what lead to some recent military disasters as well as bloodshed within Europe.

AFAIK this also was the approach adopted by the Mongols, as early as during the 13th century (Golden Horde khanate).