Also I always like to wonder how the armies of old would react if given access to todays technology.
Would they carpet bomb and fuel-air bomb the living shit out of any living thing that doesn't throw up the white flag or would they inevitably assume the moral soft warfare of today?
Depends on which armies of old from what time period.
Pre-bronze Age collapse civilizations were quite cosmopolitan, engaging in trade and diplomacy over (expensive) wars. Post-collapse, things turned to a much more brutal state of affairs.
In the early Medieval period in Europe, there was a lack of farmable land compared to people alive (and food production was based on Mediterranean 'scratch plow' and Roman slave-based farming) and often killing everyone and just taking their goods was preferred. In the late Medieval, with argicultural advances and a reduced population due to war and onset of the black death, there was a lack of people compared to territory - war leaders were more interested in capturing and co-opting populations instead of extermination.
There is also the "Horse Problem". Which I will tried to tl;dr as this:
Primitive people tend to be violent to outsiders. This is usually a needed a consequence of their environment; if you don't defend your resources, you'll find yourself without any. And when you are limited to human foot traffic, you can presume anyone inside your territory is only there to take your shit.
Once you give primitive people horses, there tends to be a period of marked, horrific violence and then a scaling back - people can now pass through your territory, or visit and then leave. Native Americans are a favored target of analysis because they were observed by enlighted minds and had been isolated from nearly all technological advancements, but the Roman analysis of the Britain Celts describes them the same way once they got Roman horse.
If your society doesn't adapt to a new innovation, they tend to over use it violently until sense starts to prevail. Constant extermination-level violence is not a good long-term survival strategy for people or animals. Even if you win your fight, you may be beat up and a less-fit but uninjured member may finish you off, meaning the fittest might not be surviving.
So you give the Babylonians a B-52 and they would be carpet bombing everyone who looked at them funny until they started to appreciate the cost. And I don't even mean the moral one, I mean the material one.