Again, the Fallout 3 lessons are comprised of stuff that's not explained. All these have explanations.
Ilosar said:
4. A small town in the middle of nowhere surrounded by giant scorpions, huge mutated lizards, raiders, and killer wasps of doom, and protected solely by a girl with a shitty rifle and a dog, manages far better than places protected by armed militia or trained soldiers, who have to face junkies as their worst threats.
To be fair, the monsters up north don't seem to travel south to Goodsprings - there's a rather sizable cliff that separates the graveyard from the areas with those giant scorpions/lizards/etc. And, as the Courier finds out, if there's really a problem, the town rounds up a posse to take care of it. For the most part, since they're so far off the radar, they can fend for themselves.
5. Apparently, charging men with football gear and machetes are more than a match for trained soldiers with guns. In a desert.
That's what the Legion believes - that honorable kills with melee weapons are better than guns. They shun technology when they can, and then use simple firearms where possible. They are, afterall, little more than tribals putting on the air of civilization.
6. The commanding officer of Camp Maccarran knows that his base is leaking info to the enemy. Also, almost everybody knows that the communications tower lights up at about 1AM, every night. Apparently, this mystery can only be solved by the guy/gal who just arrived.
Mind you, the same guy who is supposed to be investigating this, the head of Camp Mccaran's security, is in fact, the same guy who is behind the problem. Everyone else is sitting on their hands because it's not their duty to go investigate.
7. corollary to the above, it seems like, as soon as they have a problem, almost every single person prefers standing around looking distressed, hoping somebody will be charitable enough to help them for free, rather than actually doing something to fix said problem. This includes the commanders of massive armies who have enough secret agents and intelligence networks at their orders to track one person over the entire Mojave.
That's why the Courier is a hero in this story. He can do things that other's cannot. Either through circumstance - some people have to stay right where they are, or they need a little guidance that the Courier can provide.
Emily Ortal just stands outside the Lucky 38 because no one else is allowed inside, she needs the Courier to help because the Courier can go inside.
8. Cottonwood Cove could easily be wiped out by one sniper. Or a guy who happens to find the radioactive truck of death. Generally, such a valley is a pretty bad idea for an outpost in a world where guns are a dime a dozen. Yet it is still vital to the Legion crossing the Colorado. And nobody in the NCR has the idea to cut off Legion attacks at their sources.
It's the reason why General Oliver is also called "General Wait-and-see." He never takes the initiative to actively go after the Legion and prefers the stalemate where at least he has the Dam secured. Most of the soldiers, on both sides, aren't moving because of Orders.
9. If you are allied with a faction that possesses a working bomber, the best way to use it is to wait for the climatic battle, instead of, you know, firebombing a base made solely of tents and ensuring there's no battle to begin with. Same goes with an elite team of crack snipers who know the desert more than any other; fuck harassing enemy lines and sniping officers, tell them to charge like morons.
This one I partially agree with. The Bomber is just never ready before the Battle of Hoover Dam, at least not to the point where they can take an initiative to bomb the other side. To wit, the bomber is always incomplete when you go to Nellis and still being worked on by Loyal and Jack.
First Recon, on the other hand, is stuck defending Camp McCarran until the Fiends' threat is mostly neutralized. Again, under orders after a couple disastrous run-ins (see Betsy), they're stuck defending McCarran from the base walls.
10. The best way to get anything done, including breaking in a super-high security casino and changing the politics of an entire region forever, is to find the most rag-tag group of people possible and make them work together.
This one is answered with Dead Money itself. Elijah had sent other people in, having even gotten inside the Sierra Madre itself, but then the previous groups had started turning on each other. Elijah is actually trapped inside the Casino, so as a matter of necessity, he's forcing groups that would otherwise not work with each other into cooperating.
Hassknecht said:
11. The NCR is desperate enough to let a random dude with a theoretical degree work on an important power station.
It's not that they're desperate, it's that no one else wanted the job. Apparently, the NCR sent a lot of people to work on Helios-One, but they couldn't get past the array of laser turrets and robots to actually turn it on. So, the one guy working on the station is pretty much the only one interested in it because it's a cushy job. The Follower guy is just passively watching over him. Everybody else said "Hell no" and went to Hoover Dam.