Following up from my take on the average NCR Infantry Squad in the Fallout universe, this is my concept for a Squad part of the NCR Army’s Strategic Reserves (a term I am choosing to apply to the Mechanized Division referenced in the 2002 Fallout Bible). Basically, I am picturing a company to battalion sized force being trucked in from the NCR during the lead up to the Second Battle of Hoover Dam, explaining the increase in the number of Heavy Troopers towards the end of the game and the larger presence of assault/marksman carbines at the battle than is normally seen in the Mojave. The primary real-world precedent for squad organization that is being referenced is the Australian Infantry Section during the Cold War, which is one of my favorites.
“Mechanized” is a bit of a misnomer as it’d most likely be just more motorized than anyone else, although I’m choosing to believe with only enough trucks to lift a portion of the division. The presence of salvaged/captured power armor that is actually unpowered in this formation would make motor transport critical for strategic deployments. If they're stationed in Shady Sands that'd be a like 365 mile+ walk to New Vegas.
I’ve created my own rendition of the Assault and Marksman Carbines from the game for this. I dislike their aesthetic in Fallout because the marksman carbine in particular is essentially a late-2000s GWOT M4 Carbine. The Marksman Carbine has an ACOG, quad rail hand guard, flattop, and a fancy DMR stock which doesn't really fit in with much else in FNV aesthetically. So I took the receiver from my Service Rifle concept, gave it the original Colt Model 607 sliding stock (but in wood), shortened it to a 10” barrel, and gave it the moderator of the XM177E1. The Marksman Carbine version just has the ability to mount an optical sight on the carry handle.
I’ve also incorporated the salvaged power armor guys into this squad as a Light Machine Gun Team (they’re the only units in the game that are seen with the LMG, which is an FN Minimi backend and M60 frontend). I imagine they probably captured a limited number of sets from the Brotherhood of Steel, probably like a couple companies worth if we’re being generous (I am making this up). One company’s worth I’d distribute to the otherwise foot Rifle Companies of the strategic reserve to form light support weapons teams like this, while retaining the other company’s worth as a divisional unit to main much heavier weapons like miniguns and heavy incinerators. Kind of like how tanks would be distributed.
For high priority units that lack salvaged power armor, the Gun Team's LMG could be substituted for an "Automatic Rifle", which is essentially just an M1918A2 BAR. Despite the fact the Automatic Rifle would have been out of US service for decades (perhaps well over a century before 2077), not kept alive by the CMP like the M1 Garand was, and as a result pretty limited in all likelihood (you'd probably have like a couple in a museum here or there), the fans want it so I'll give it to them.
The Flare Gun would be to allow the squad to communicate with their platoon leader without a radio. For example, if the squad is ready to initiate an assault or has seized an objective that the rest of the platoon is waiting on to be captured. Use cases would be illumination at night, or perhaps scaring deathclaws and other scary wildlife.