Homelessness is an effective way of hiding the symptoms at the cost of hiding the whole human from society. How many homeless lives are in the historical record? To the extent that they are referenced at all, they will appear as beggars in the background of some wider historical event.

You can beat symptoms out of someone if you don't care whether they survive the process. Then you have no people with visible symptoms around cluttering up the place.

But that goes back to the author's point: some mention of many beaten-to-death veterans would've received mention in ancient works but doesn't. And that's setting aside the idea that beating up a veteran who's primary combat skill was close combat, unlike modern veterans, was something easily done.