AI will never be superior to humans. OODA loop is just a framework for decision making,
but the idea of a super-genius perfect Courier is a projection on your part to what the Courier should be when Dust makes him a more fallible character, and there's nothing wrong with that inherently.
Boy you completely ignored my comments on Securitron feat of wiping single platoon of soldiers. You know how serious that thing is? Our freaking modern quadcopter drone, armed with single grenade or mortar round can wipe out single squad of soldiers without the humans noticing that they are being targeted. This is platoon bro. Why you don't adress that first? Like what kind of tactics NCR will use?
And remember, Securitrons are just one type of weaponry that someone like Courier 6 has in his arsenal. But a single Securitron is confirmed to be such a force multiplier that a combined arms tactic will definitely killing off any invading force.
You also ignored my comments about static defense, you think NCRA gonna going through it like walk in the park if Courier built some nasty trench, smart mines, mortar holes, force field, all kind of missiles systems, and MG nest?
Also regarding battlefield communications and AI advantage of it. Majority of casualties of American force in Gulf War and Iraq War are through friendly fire. There is reason why they have entire airmen units, entire special force for Identification Friend or Foe. And the fact that NCR operates more or less through WW2 style radio communication. This obviously cannot be compared to Securitron's wireless communication whose OTA update allow something as simple as recognizing which shades at that distance are friend or foe. This is particulary important during nighttime engangement or when battlefield is obscured. So OODA loop is clearly favor toward networked AI, the kind of wireless broadcast that allow instant transfer of different type of AI personalities. NCRA clearly don't have anything similiar to modern day FCS Network, whom when compared to Securitron network doesn't seem to be that superior.
I accept the ideas of not-so perfect Courier 6, Courier who never bothered to plan for long-term game. Courier 6 who rush through all quest, barely consider the future of the region. Though, I will be careful from saying AI will never be superior to humans. Especially in the context of Fallout world. They got supercomputer that emulate the neural pattern of human brain, which ZAX is.
So no, the idea of physical aimbots who are connected into wireless network able to destruct conventional army is not foolish. Speaking of robots, The semi-canon war of The Calculator Robots vs Midwest Brotherhood of Steel should be your go to reference how this hypothetical war can be won. A surgical attack of very experienced PA warriors, armed with actual freaking nuke warhead, and bear in mind that this is more suicidal attack than a military operation with plan B.
While talking about ongoing war like Ukraine war can be controversial, but there is no denying here that in the early phase of war, Russian communication was crippled enough to make the whole invasion stalled. Not to mention that plenty of high ranking generals were killed. This is how conventional army fares, against relatively same human force, perhaps with better coordination. Human conventional army vs robotic force with actual AIs? No Nahh...only insane mind would think the former can be superior. You need freaking John Connor style of warfare waged even for that.
But this is just one pathway that you make and plenty of us here criticize Chris Avellone for making the only path forward is through re-destruction of society. Fallout is post-post apocalyptic, and the main appeal of Fallout New Vegas is that. For each games, you get to witness the action of your previous games main character, shaping the society and how nation grow. For Fallout 1, 2 and NV we get a good contrast how NCR vs Brotherhood of Steel progress. Even Bethesda games took some notes from this, as we seen in Fallout 3 and Fallout 4 Lyon's Brotherhood transforming into Arthur Maxson Brotherhood.
Without the Legion, the NCR could easily come after the Courier on all sides, from Reno to the North, Long 15 to the West, Utah to the East, and Arizona to the South. The Mojave ceases to be a one-sided filter for the NCR when their biggest enemy is shattered.
Except Long 15, everything that you mention there are much easier to be accessed by Courier first and fortified by his/her force.
Like come now, how much you think Reno was annexed? Do you think moving goods and people from Shady sands through there is easier than through Long 15 and Ashton-Hopeville (Dead Valley region)? Northern Nevada is not fully controlled by NCR, not even full state and there is always risk of harassment and distruption for going through that region.
And Courier's Mojave state is closer to Utah, Arizona and the East than NCR. So what's your point here? NCR under different presidents are not able to finish the whole supply line problem in span of 7 years, let alone invading from much greater distance. This even assuming that Courier 6's state will not expand further (and boy he will, thanks to the advantage of material through the SM. Vending Machine).
TLDR: human piloted drone > conventional army
Fallout AI > human piloted drone
The Calculator's army => Yesman's Securitron > Fallout AI