Yes, I am mostly talking about Stoicism, but the older philosophers that the Stoics revered like Socrates were often discussed or admired by Stoics more in the context of their personal lives, rather than their philosophy.

Socrates, Xenophon, and Plato were all soldiers or military leaders. Epictetus was a slave that was crippled from abuse. Viktor Frankl and James Stockdale are both fairly modern people that survived extreme hardship using stoic ideas.

That seems to be an argument also for religion. Plenty of people also survived extreme hardship using their beliefs.

Not saying there is anything wrong with this thesis, but I want to point out that this is not what philosophy usually thinks of itself, and it may not transfer. The philosophy the helped X may not help Y under similar circumstances.

I think the lines between a practical philosophy, a religion, and a psychotherapy technique are pretty blurry. In ancient Greece and Rome, people would often identify with a philosophical school in the same way people identify with religions nowadays, choose them based on the practical benefits, and practice them as a lifestyle or religion (instead of just conceptual understanding).

I don't think it's mysterious or hard to predict where techniques from a philosophy or religion will be useful in real life, and where they will not... it's pretty easy to understand what they are, and how they apply. Modern therapy techniques like CBT, ACT, and Mindfulness therapy are pretty much just extracting these ancient ideas and practices in a systematic way, so they can study the effects clinically and actually be able to say in which real world context they are reliably useful.

Wasn't Plato a wrestler who would occasionally win arguments by just flexing? Or have I been mislead by internet pop culture...? :P

He was a wrestler of some renown in his youth and his coach nicknamed him 'Platon,' after his size or big shoulders (depending on who's telling it). Winning arguments by flexing is apocryphal, as far as I know.

It also doesn't really sound out of character, in a general sense. It's not like being an ancient philosopher also meant you didn't have a sense of humour (assuming the flexing was humour, if true).