If you had a machine that was able to get a rough idea of someone's physical capabilities, you would use it. Sure it may come across as creepy, but it's more important to, IDK actually see how the gunshot victim is doing. Why is it the worst possible location?, It's isolated from the rest of the town. Also, as mentioned above, Goodsprings gets there water from The Goodsprings Source, not from the water tower. Or, y'know, maybe it's a fucking coincidence. Erm, no, Crimson Caravan Company(Which it is hardly ever referred to as in-game, always being called "Crimson Caravan) is a reference to the caravan company that does dangerous routes in Fallout 1. Or y'know, maybe they just used a name that was a reference to something without the character themselves being a reference. Like, if you needed to come up with names, you'd use names you were familiar with, but not necessarily base said character off of it. Legion has access to Firearms. Every single attacker at Hoover Dam had some kind of modern weapon on them. The Legionaries that only have spears and machetes are "Recruit Legionaries" who are found around Nipton. They don't get involved in proper battles because they have yet to prove themselves worthy of the Legion. Also, NCR only has a limited number of vertibirds. They don't have them in enough numbers to be used seriously to fight them. ALSO, don't forget that this wouldn't be the first time a modern military struggled against a relatively less advanced group. The Vietnam War was pretty much a modern military getting its ass kicked by a bunch of rebels.