It was pretty common practice .. by some extremely aggressive groups .. from ancient through to modern times .. by war-like nations. Yes Romans.. not everyone did this worldwide. The world has been wounded repeatedly by the extreme brutality of some armed groups. It is simply false to ascribe this behavior to "pretty common" without distinction, and IMO makes the horrible into some kind of banality.
I would argue that the groups you label extremely aggressive were just the winners, and the other “less brutal” groups would have done the same thing if the boot was on the other foot.
