"the song does question the idea that conscientious objectors might act differently when the proverbial threat is at their own door" -

Again, a problem I have with the song: Why on earth pick on conscientious objectors? Hardly taking on a pressing issue, or a menacing group of people - unless the song is intended as an obscure swipe at draft dodgers - which I don't think it is, and if it were, it would be so obscure as to be ineffective ...

"he took many shots at those positions he judged to be less than manly in the macho, maybe Ernest Hemingway, sense." -

To me, it is misleading to equate Stan's outlook - as revealed in his songs; I never met the man - with that of Hemingway (your hesitancy on the point noted). While there is an overlap, Hemingway's machismo is that of the privileged man who needs to seek out challenges to test his manhood; Stan's is that of the unprivileged man who must respond to the challenges life hands him, and the challenges that interest him are those that relate to family, work, and community. Hemingway's protagonists typically go sport hunting and sport fishing; they seek out exotic locales; they are isolated from family and community even when among them; they do not need to do menial physical labour. Stan's fishermen and seamen are working men; sometimes their work takes them to exotic locales; they work hard and take risks for their family and community, including their fellow workers. Hemingway's machismo is of an elitist variety - the superior man demonstrating his superiority, while Stan's is of an egalitarian type - the ordinary man demonstrating the strength it can take to be an ordinary man. All this is probably why, while it is popular to sneer at Hemingway's machismo, you don't hear people sneering at the corresponding aspect of Stan's outlook - in my limited experience, anyway.

"I intervened, got between the two of them, put my hands on his 2 shoulders and pushed him back" -

Okay, so here's you, presumably a not particularly war-mongering or warlike folk-singer, no doubt rather surprised, maybe even shaken up, by that night's unanticipated events - but was the idea that someday some situation might arise in which you would be moved to defend your wife entirely new to you? Were you surprised philosophically? I doubt it - I doubt ANY man reaches adulthood - let alone late adulthood, as in the song - without considering that he may someday feel that he should defend someone he cares about. I suppose I'm flogging Harris's dead mare by now, but that's part of why the song just lacks credibility, to my mind.