Well for the first part there, I suppose it depends on which devs we're talking about with regards to at least how similar the narratives the old world blues nerds and the dev nerds are riding with each other.

And looking and all the doohickies and tweaks the old world blues nerds made in making divisions like a scant hundred or so men per division slot for a block of infantry being drawn up in context of how large west coast America actually is, adding in the fact that the two largest factions being NCR and Caesar's Legion, have plenty of land with people living on to draw from, I'd reckon its still a bit generous but a fair heaps closer to realistic scale warfare in the fallout universe.