Militaries do not think like this. They do not plan like this. If they did, they would only allow gay men in the military. In fact the opposite happens. Your theory doesn't match reality.
I'm not talking about the modern military. I'm talking about the constraints under which humans evolved. I'm also simply looking at it from the assumption that all the players are rational actors, and the rational choice is to maximize chances of victory in warfare.
I think the modern world is much more complex, and the rational choice in general (possibly even in antiquity) is to avoid violence if at all possible and find mutually beneficial solutions to resource scarcity.
