To be fair, do we know if those women are even fertile? I imagine in a world where one of the big problems you face in everyday life is most of the water being more or less permanently radioactive one of the more common problems would likely be infertility. Could also go a ways to explain the overall low number of kids in the games. I mean, every single settlement throughout 3, NV, and 4 has very few kids outside of Little Lamplight in DC. Just a tiny handful compared to the adults no matter the settlement.
Fallout tends to work on the "magical radiation" logic, especially with the FEV basically accelerating any and all adaptations to the horrors of radiation. So infertility would likely have been solved after 200 years through natural selection favoring women who are still fertile.
the lack of children can be moreso blamed on the fact that there arent a whole lot of ways you can make child npc's interesting, especially in a setting that deals with grittier subject matters.
Sure, that might be some nice NCR propaganda, but in game the Legion is all for utilizing guns, they just reserve the higher powered and more advanced weapons for their veteran soldiers. No different than the NCR giving their Rangers anti material rifles compared to the average NCR grunt receiving some service rifle that's halfway broken. The state of such weapons also gives this strategy of melee more teeth, since the average soldier doesn't have access to near mint condition weapons like the player character, thus having actual skills in handling bladed weapons makes the difference between a victorious Legion soldier and a dead NCR grunt.
I also see it as a way to integrate gameplay into the overall story. Yeah in our world trying to melee a bunch of soldiers with guns is idiotic, but in the fallout universe it's a perfectly valid strategy. Just like you can fistfight a deathclaw or tank a shot of plasma to the face, fallout humans are more durable than real world humans.
As someone who detests the Legion, my dislike for the Legion, or more specifically, how they are written comes from the fact that they are treated with kiddie-gloves in terms of realism. The NCR have realistic logistical issues that makes them unable to properly wage war and defend their territory. The Legion meanwhile manages to become a widespread threat entirely through the power of a having a go-getter attitude and a big book of roman words.
NCR grunts are made out of paper, with out-of-date kevlar and less-than-optimal rifles.
Legion gigachad warriors wear football armor and can tank bullets with their foreheads.
NCR grunts are few, scattered and disorganized despite having an entire national apparatus supporting them, with access to radios and a long-standing military tradition that should help in coordinating a military effort.
Legion has an inexhaustible supply of suicidal devotees who gladly charge into battle with machetes and spears.
NCR grunts struggle to take down ants and fire-geckos, despite being in squads of 3-4 rangers armed with carbines.
Legion Ascended nephilim centurions beat deathclaws to death with their big swinging dicks of doom.
The only way the Plot Armor could get more on the nose would be if Caesar himself was actively partaking in battles.
This is incidentally why, whenever i play NV, i always download mods that turn the Legion into something less pants-on-head retarded. Actual armor and using guns.