"the males may feel it their duty to protect them from harm...a natural reaction which could have a bearing on the effectiveness of the unit."

in combat, a bond forms with your "buddy"... and your unit... until losses become so great, you don't even bother to learn the new guy's name. Read Audy Murphy's "To Hell and Back".

and if females are so "precious"... why are they subject to murder, rape, etc. by invading soldiers?

It makes as much sense as dragging the silverware over the ice by the Franklin expedition... an unthinking response to conditioning... well conditioning is a two way street.