It depends on the professionalism of both the men and women of individual units.
There are exceptional individuals of course (ie. the women detached to SF acting as Cultural Support Teams) who could probably outperform a lot of the male candidates. That said, if you're looking to put thousands of people into the combat arms, the majority will be average joes and janes. A platoon of 60 guys is going to last longer than 60 women when you put them through training. Mental stress correlates to physical stress and women are at a disadvantage physiologically.
This is not to say individual women are incapable... it's to say men and women have certain biological differences that makes training women less cost-effective. The problem here is the issue of individual rights vs. the effectiveness of the organization. Some might say that's not a problem, it's a victory of democracy -- the twist being the well-being and even survival of the individual in war may depend on how well the unit functions.
This argument is for the most part theoretical wankery. In the IDF (Israel) all trades including infantry are open to women. I think female representation is still very low in the combat arms, and it always will be. It doesn't really NEED to be restricted because at the end of the day, women either don't really want to dig trenches with a pickaxe for days or are smart enough to know better. A lot of girls will yap about equality but let's get real... the reality of the infantry will turn off 98% of women when they actually have to face it, much less ground combat and killing in war. This will always be a man's world, and young at that.
I've never seen feminism advance a theory of how to direct armed violence, beyond the obvious fact of stating that war is bad for all of us. This really interests me. It's an uncomfortable thing to admit as a woman that your most powerful foreign policy influencer is
organized violence effected by males, and that women want no part of it. It's also your most essential, frontline means of protection of women (ie. the 150 SF advisers sent to Liberia to tackle militias using rape as a weapon). This is an ugly, ugly paradox when you're trying to convince men (well, the ones who listen anyway) to renounce violence in general as your key strategy to reduce the vulnerability of women.
Anyway that's quite a tangent! The point is that theoretical wankery usually dies when it's time to walk the walk. Women and men are different, and always will be. But hey I'm sure the guys don't mind the girls on the morning PT formation right?