"Women and children first" only means something in mass transportation or dense urban evacuation in a society with a concept of queueing.
More generally, there are ancient virtues of preserving the precious, vulnerable and honored, but the situations where the men would have to uselessly line up in the back would not exist. They would be fighting, attacking back, carrying weaker people, creating diversions, etc.
I think you're close to the mark but not quite on it.
Women and children first is an artifact of modernity. It is a required value in a location where you can A) have a disaster and B) have people (men) who don't have strong bonds.
If we were all from the same family, or village, then yes your "preserving" line of thought works. But mix in a group of males who dont have women or children with them, they can push to the front as it were. Even if they don't have the numbers to be successful they are a "threat to order" that might not exist. One where men who could be helping are now fighting/keeping order.
Yes this. Even though it has been practiced for years prior at some point it was probably just instinctual and driven by emotion instead of logical thought.
The phrase and it's propagation is an artifact or modernity.
More generally, there are ancient virtues of preserving the precious, vulnerable and honored, but the situations where the men would have to uselessly line up in the back would not exist. They would be fighting, attacking back, carrying weaker people, creating diversions, etc.