Indeed. And I believe the New Vegas Brotherhood is more representative of the overall Brotherhood than Fallout 3's is. In Fallout 3, the Brotherhood wants to help the populace, fight against the Enclave, secure water, protect the people... Whereas the Outcasts call the people stone-banging monkeys and are only interested in preserving technology. So I'd say the Outcasts, too, resemble the common Brotherhood chapter.
You could base the Brotherhood of Fallout 3, but I believe the reclusive and inevitably dying out Brotherhood is the common / main one, so to say.
The NCR, too, has taken a turn for the worse; ranchers dominate politics (the 'corporate America' you refer to), they're expanding rapidly, leaving a mess without proper security, government, and integration with the main NCR behind... Though I can see the NCR turning 'good' again, as they were once before. Who knows.
How do you mean weighted? The end result of their victory? Well, for my own mod, I added a New Vegas faction with Robert House (Mr. House), Benny, and Edward Swallow (Caesar) as leaders, representing all possible ends of New Vegas except for the NCR one, because I couldn't find an NCR leaderhead.
On that note, I notice you have a Tandi leaderhead in-game...
But, I did write up a tiny paragraph of how New Vegas would turn out under their respective rules, for the Civilopedia. I doubt it helps you, but why not share it:
Under Mr.House's leadership, New Vegas will become an independent power, financed by trade and commerce. A place of stability in an anarchistic wasteland of death and destruction, guarded by an army of robots, Mr.House plans to reach space within decades and to establish a culture of science and commerce.
Under Caesar's leadership, New Vegas will become part of his empire, standing for safety and stability in a land of lawless savagery. Trade flourishes within his empire, as people are protected by law and force. Thanks to the extremely harsh penalties - crucifixion, slavery, an eye for an eye - banditry practically disappears. Of course, a sexist, militarised, autocratic empire may not be the perfect place to live in, but it is an empire that provides food and safety, and that sure beats living out there in the wastes.
Under Benny's leadership, New Vegas will become a capital of gambling, debauchery, and nepotism. Benny is the unquestioned leader and enjoys the pleasures of life, revelling in his power yet seldom exercising it beyond ordering free drinks and prostitutes. He's a simple man, passing his time with drinking and gambling, without much of a desire to expand the borders of New Vegas. He has plenty of 'friends' and loyal acquaintances, whom he often rewards with drinks, drugs, and other such benefits. A friendly enough man, and a true people's man, he has little to fear and has established a paradise for those whom others would call immoral or decadent. But there is no way his New Vegas can survive for long, when - not if - others, such as Caesar's Legion, decide to get involved.
EDIT: Also,
diplomacy text, should you need it. Most of it is taken from what they say in-game, though changed here and there to fit in with Civilization IV.
