This was the same argument used by men when I got into law enforcement to try to keep us out. I passed the exact same entry tests the guys did. The only difference in requirements were height and weight minimums which were adjusted for the different sexes, but the body pulls, runs, push ups (standard push ups too, no "female" style allowed), sit ups etc were all the same. The only test I had problems with was the 6ft wall . That was because I had a guy trying to tell me how to get over the thing using nothing but upper body strength. When I figured out to ignore the man and use my head and figure it out myself, I did just fine getting over it. Not that it ever came in handy. In all my years on-duty I never had to jump a 6ft wall (and never saw any guys try to do it either). I never had an incident that any lack of brute upper body strength prevented me from getting the job done.
Point is, guys like to use "brute strength" as an argument to keep women out of combat positions. But I think women in law enforcement have shown for many years that using your brain and figuring out your way around a problem is just as valuable, if not more so, than bullying your way through using all muscle. Would I like to have as much upper body strength as guys do? Sure, but adrenaline is an amazing thing, and women have moved people and things with it during high stress situations where men would not have thought they could. The argument is way past old. It's about time the military is doing away with artificial barriers.
And before someone points out that some hand-to-hand type combat positions are much more physically demanding on a regular basis that law enforcement, I don't dispute that may be true, but come on... on a submarine? Good grief.