here's Demilich. First of all, it's kind of funny that all these guys kind of look like each other. Secondly, again, these guys do not look cro-magnon, or "harsh," in the least. The man in the forefront (is this Antti?) actually reminds me of Ildjarn because, again, there's something "neutral" about the way his face looks, maybe not androgynous, but not overly masculine. he almost looks like an alien or something - same thing with Ildjarn.
here's a younger Bathory. And here: http://i194.photobucket.com/albums/z50/Gawenbass/Quorthon5B685D.jpg I obviously can't confirm that this is, indeed, Quorthon, but assuming it is, he's clearly a handsome man. Not "harsh" or overly masculine, at all. Again, I don't think it's that crazy to say he has some "feminine" features.
In summation: between Ildjarn, Varg, and Quorthon, at least, I don't think the innovators of metal look cro-magnon, or "harsh," at all. They're VERY "fair" looking.
let me also make a point about good looking women. I happen to think that some of most beautiful girls I've known, and some of the best lays I've had, have actually been women who are slightly "Tom-boyish" in looks and personality - taller, athletic build, don't need a lot of makeup, they have a "manly" libido. these are the kind of girls you want to settle down with. they're a better lay and they're not consumed with their looks.
so here's the point: it doesn't surprise me that brilliant men have feminine features, and it doesn't surprise me that great women have masculine features. let's face it: we're as much a product of our father as we are our mother. every male has some female in them and every female has some male in them. In the Jungian archetype terminology it is anima and animus. A well-turned out person has their anima and animus in balance. in the Jungian archetype scheme, when anima and animus is in perfect union, it is called syzygy.
Human sexual dimorphism is considered to be relatively low compared to other animals, and I have to agree with your assertions.
There's actually some masculine characteristics, like facial hair, that we are forced to shed in order to seem "non-threatening" in modern society, like the beard, which serves the same function as a lion's mane, being a secondary sexual characteristic, which designates off-hand that the person is a male.
Quoting the Wikipedo:
"In the course of history, men with facial hair have been ascribed various attributes such as wisdom and knowledge, sexual virility, or high social status; and, conversely, filthiness, crudeness, or an eccentric disposition, such as in the case of a tramp, hobo or vagrant. In many cultures beards are associated with nature and outdoorsmen."
Masculinity is threatening and taboo for some reason...