I would guess a key difference is that these soldier according to this article deserted the Irish military. Militaries tend to frown upon people leaving on their own schedule.
You wrote: “Militaries tend to frown upon people leaving on their own schedule.”
In particular, the Commanders of the Roman Legions frowned upon soldiers who mutinied, DESERTED or who had been derelict in their duties. For these offenses, an entire unit would be subjected to “decimation” in which one out of every ten legionaries, chosen by lots, would be beaten to death, usually by the other nine with their bare hands.
I often hear reporters talking about the “decimation” of cities, etc.... men of military units are “decimated.”