in any world, real or imagined, where the human population is under constant threat (as in, "There aren't enough of us"), men will inevitably be regarded as the more disposable sex, the sex that any given human group can afford to lose in a war. This isn't about gender, it's about biology. It is easier for a group to rebuild from a few men and plenty of women than from few women and plenty of men. For most of its history humanity was chronically short of person-power - partly because it's so fond of fighting wars, partly because so many children died in infancy. Things are different now: we have more people than we know what to do with. This has facilitated our liberation from the tyranny of biology. I'd add that while there will always be a percentage of women who like nothing better than a battlefield, the vast majority of all human beings, men and women, go to war unwillingly, and would get out of it if they could.
The Swiss army has allowed women to do military service for quite a while now. Remember, this is a country that has practically no professional soldiers, and which provides excellent education and employment opportunities for its young people. In Switzerland you wouldn't go into the army because you're poor and are looking for training and career. I see a lot of Swiss soldiers around. I see a few women soldiers. I don't see many.
Most magical/fantasy fictional worlds have a tendency to glorify war and those who fight it, and I'd argue that that in itself is a patriarchal way of looking at the world. War is so shitty and awful in reality, it has to be glorified in fantasy, otherwise all the young men who go off to fight in it (imagining they're off to some big adventure) would "shoot their officers and go home" instead.
