I probably agree that the main differentiating factor is  muscle mass and bone structure. But you're discussing this in a simplistic way. We need to think about this within the context of a double bell curve.

Williams, perhaps the best female tennis player, might lose to most of the male professional tennis players. But she would still beat 99.99% of all men.

But I'd rather address your paragraph about women in combat. I'm not a strong man. I'm 5' 4" and I've spent a lot of time in my bed reading books. Let's hypothesize that 75% of men are stronger than me. Let's assume the deviation of the curves is such that 55% of women are stronger than me. Assume I have the minimum strength to be in the infantry. 25% of men and 45% of women lack the physical capability to qualify for combat duty. That still means that 55% of women could be combat qualified and some of the strongest women in the infantry would be stronger than some of the weakest infantry men.

Of course these numbers are made up to illustrate a point. But clearly, if one looks around the world or watches even the small amount of sports I do, there's at least a significant minority of the strongest women that are stronger than a significant minority of the weakest males.

We surely do know that steroid hormones affect surely muscle and bone!  And therefore things like power of limbs. That's why body builders (and baseball players famously sometimes) take them and why Olympians take drug tests...why some female Soviet Olympians in the past looked like men.

Who has not seen a lesbian dyke who looks like one of those Soviet Olympians naturally as if she could lift a truck? Why do you think that is? Her natural mix of hormones.

Some women have the right mix of hormones that can build a body to compete as well in certain sports where more men have the same. There is definitely the effect (also well known to body builders) that the right diet and exercise make much more of that which you already have, from childhood on.

Then we must not forget that most highly competitive sports were developed by and for male bodies from the getgo.

Create a highly competitive sport where fine motor skills rule and more women will be better than men at it. This does not mean some men will not be great at it too.

That's all I was saying. Including that we truly don't know much about the body's hormones yet, it is a particular interest of mine. That issue happens to rule the whole why do people get fat thing. And the diet thing. Every individual is different the way they process forms of energy. Scientists are continually finding out that when they come out and say something like "refined flour not good to eat" it is not true for every person. They don't understand why so many insulin pumps go haywire with the modern diet, because not everyone's does. It's the evolutionary mix, doh. Enough women keep playing tennis long enough, like a couple thousand years, they will on the whole become as good at it as men, I figure.

I think after feminism freed some of the nurture things up, the pendulum has swung too far overemphazing the role nurture plays in some things. End up making people feel guilty for following their bliss, for following that which they are best at simply because they have the natural skills to excel doing it. That's a moral issue with me, I think it's not fair to make current people the guinea pigs for a more equal sexual world far in the future due to evolution. If that happens naturally, it was meant to be.

On women in combat.

Watch this recent BBC video from Raqqa to see a Kurdish female soldier actually aglow about her newfound love of killing people that she believes are her enemy. She's fairly feminine in appearance. She basically tells the reporter that she's found her bliss, her mission in life.

We don't really know what makes people "good" at this. Recruiters in the past wanted brawn because they needed brawn to tote that barge. They mostly don't need that anymore. I'm thinking agility and quickness and ability to be calm and rational under fire might be key these days if you are going to have a lot of urban fighting.

I just posted this story on In The News  that too much of a single hormone, testosterone, commonly found in higher amounts in men than in women, though women's bodies need it too, seems to make for poor judgment of risk and rash decision making. We are only now just learning this because lots of men are taking it as they age and as levels drop, for supposed increased stamina, stopping muscle loss of aging, etc.

We don't know what else it does. Because: it alters the whole hormonal system, and no doubt effects on individuals will vary. Andrew Sullivan wrote famously about the physical, emotional and intellectual effects on him of supplemental testosterone in a relatively short amount of time in a 2000 NYT Magazine piece "The He Hormone." 

Whatever else it does, too much testosterone clearly not good for a sniper.