One of my favorite historians is Christopher Beckwith, a provocative but also very interesting scholar who likes to write particularly about Eurasia and the "Silk Road." I just finished his book Empires of the Silk Road.
One of Beckwith's central ideas in the book is about the comitatus, a unit in warfare which Beckwith says was central to the armed warriors of very many different groups, including Scythians and Germans. The comitatus were the "friends" or "companions" of the king, who were expected to remain loyal to the king and to be rewarded by him. In particular (as described, for example, by Tacitus in The Germania) it was considered a complete disgrace if the leader fell in battle and any of his companions survived; they were expected to defend him to death and, if necessary, die with him. Anyone who survived was infamous for the the rest of his life. (As a quick aside, his would seem to shed light on the famous "last stand" of Leonidas and the 300 at Themopylae).
Compare with Vatican Sayings 56-57: "The wise man feels no more pain when he is tortured than when his friend is tortured and will die on his behalf; for if he betrays his friend, his entire life will be confounded and utterly upset because of a lack of confidence." (I am quoting from The Epicurus Reader by Inwood and Gerson, which I bought because Emily Austin recommended it.)
Anyway, all this is background, because I wanted to share a quote from Empires of the Silk Road. In a section suggesting that Central Eurasians influenced Chinese and Greek Philosophy, Beckwith writes, "Do the social and religious ideas of Central Eurasians, including the importance of friendship and the beliefs behind the comitatus, imply philosophical positions or interests, such as the quest for happiness, or the perfect state?"
He doesn't mention Epicureanism specifically, but it sure would seem to apply to the particular Greek philosophy we are interested in. Do any of y'all (correct English plural of "you," in Oklahoma and in the South) know of anyone else who has talked about the possible connection between the comitatus and the Epicurean idea of friendship? Beckwith kind of tosses it out there and moves on, but it seemed interesting to me.