The jealousies and rivalries for the attention of women destroys unit morale. The Navy might be able to put up with that on big surface ships but it could be lethal on small combat units near the front. It’s beyond crazy to be trying it.
Absolutely. There will also come to fore the almost irrepressible instinct of those same said young men to protect a woman in a potentially dangerous situation, their ancient impulses telling them that to do so will make a female more attracted to them. And for their part a young woman, driven by the same unconscious impulses might find herself attracted to such a male, to the consternation, and as your pointed out, the jealousies of their peers, male and female. All of it mixing together in the incredible, relentless, nearly irresistible, emotionally complex and near ceaseless rutting, preening and mating of our species. What a combination. Young men and women, virile, testosterone and estrogen fueled, high tech automatic weaponry , violent killing and violent death. In a way it almost seems that sex is war without weapons.