An awful lot of those sayings are extolling "willingness to commit violence" as a virtue. That's not the sort of society I think we should emulate.
Usually you see these people pop up when discussing societal norms in the 3rd world but they do pop up frequently enough to be noticed when discussing history.
When you have reckless people attacking the elderly you need better psychological healthcare and a better social system to prevent that.
I understand your point and in a narrow context it's definitely true, but in a larger context you can prevent most violence by changing society.
There's a variety of reasons for this, but one of 'em is that in a condition of systemic governance, there's some societal pressure against the kind of sadism you mention. In a world like Sparta, it's hard to tell the heroes from the villains, and anybody might lash out at any time. Even the quotes given, spell out situations where random violence was just a part of everyday, expected life. This causes tensions and grudges.
Most people doing evil things are in part doing these evil things as a result of their circumstances. By changing their circumstances through social programs you reduce violence and make everyone happier as a result.
You can argue that blaming violence on circumstances ignores people's own responsibility, but I believe that better social and medical programs are still worth it because they attack the part of the root cause society can influence most easily.
Something like this: https://www.youtube.com/watch?v=2pLb_uc0bo8
The potential to commit violence can be reframed as strength. It's useful because it grants you negotiating leverage, regardless of whether you are the aggressor or defender. Can't defend yourself? Vae victis.