For one thing, I like violent movies (as opposed to IRL). And Uther's rape of Igrayne is part of the legend, therefore it has to be there. The focus of pre-Raphaelite art on the non-violent subjects can be construed as a romantic gloss on what was, after all, a violent time.
You termed the film Pre-Raphaelite... I just felt that was a mislabelling. I only watched Excalibur once, and it was when I was twelve. I only remember the parts I disliked; I'm sure it has charms I didn't appreciate. I know the Middle Ages were violent and nasty (the combination of sex and violence were what I disliked, also realistic but artists can choose to imply rather than show) I liked Blake breaking the guy's neck; he was in a bad situation and it was required. I prefer Cally-the-guerilla to Cally-the-maternal. I liked Avon's wade-in-blood speech because it underlined that revolutions aren't clean. OTOH, we see Avon, in RoD, at the end of the 5 days torture. We don't actually have to sit through what puts him in that state. I agree with your point that *realistic* depictions of violence *can* remind people why violence is bad. Provided they empathize with the victim rather than the viscious, at which point you get desensitization.
Why waste men
simply to show off their willingness to die? Then you have fewer people to actually fight with. I'll bet the British commander did no such thing.
Well, he didn't, of course, because he couldn't. And he lost serious face as a result. So there was nothing stupid about Cetsewayo's little demo - for a handful of men he could amply afford, he soundly humiliated an arrogant colonial power.
I rather think their families may have had some feelings about whether that handful of men could be afforded. So, humiliating an enemy is good enough reason to kill your followers? I'm afraid I cannot think that way.
But then, I'm very tired and should probably be napping instead of posting right now. Wish me luck, friends, tomorrow I find out whether, after days of getting exhausted sitting in a confy chair writing to my friends, I have the strength to get through a day at the office.