I think that a soldier would by definition be a free man (not a serf or a slave), so it's not too big a jump. You wouldn't give weapons to your slaves, for your own safety, though you would bear arms yourself; and you'd be likely to refer to them as 'boy' or 'girl' even if they were older than you, their owner. Both ways, you'd be the man and they wouldn't. A state that a free peasant would aspire to ...
In Afrikaans, k^rel (there's an e under the little hat!) is pronounced rather like the American way of saying Carol; it means chap or bloke, a man you have an informal relationship with and feel friendly towards. Same word, changed meaning.