I had a thought. While I know this worldbuilding does not directly utilize game mechanics, I wondered if ghouls are considered a lesser template in this. In the sense that they lack a supernatural tolerance, etc.
For me Fallout Ghouls and Super-Mutants would be better represented by Merits and/or Conditions. Notably because they can become Major Templates in my book.
Main Faction : The New California Republic
The good book says the kingdom of heavens is like a mustard seed growing to a tree so great all the birds of the sky come nest in its branches. The NCR would say the comparison. Their story begins with Vault 15 who by happenstance, oversight or deliberate malice had been both overpopulated and harshly divided. When it opened, three groups became raiders forming the Khans, the Jackals and the Vipers. The last founded the township of Shady Sands and was persecuted by the others. They were delivered by the Vault Dweller on their quest to fetch water to their thirsty people. How things have changed. Shady Sands now may be one of the greatest cities in the wasteland, perhaps the greatest city which is not squatting on the ruins from the time before. The New California Republic grew after the passage of the Vault Dweller, devouring the cities they had walked and adding them through trade and diplomacy. The Hub, Junktown, the Necropolis and its ghouls, the Boneyard who was once Los Angeles? All now satellites orbiting Shady Sands, and it didn't stop there.
From what they know, the New California Republic is the largest state in the Wasteland. Nobody can say for sure but the elders of the Brotherhood of Steel who have the most complete map of the former United States tend to agree. Caesar's Legion may be a contender when they will assert control over both Arizona and Colorado, but for the moment the NCR is supreme. Its northern territories stop just shy of the land controlled by Arroyo. It snakes along the Pacific save for the Shi-controlled San Francisco and is bordered by the Mojave to the east. There are lands remaining in Baja outside direct control but it's only a question of time before they bend. Renowned city-states like Vault-City and New Reno are so caught in the orbit of the Bear, they may be vassals in all but name. They may yet be won in peace, choosing to be fully assimilated. They may yet be won in war, the Republic's armies are vast especially in these times of expansion. Yet for the moment their eyes are fixed upon New Vegas and Hoover Dam. The Republic may compare itself to the mustard tree of the good book, or the seed fallen into good earth, but for its neighbors it is more akin to a strangling vine who creeps ever slowly towards them.
Politically speaking, the NCR considers itself a democracy. Its representatives and senators are elected through universal suffrage. Still the executive branch of the government, the President and its cabinet have massive powers, especially military as they can declare wars and negotiate peace of their own accord. Moreover the Republic while having passed recently its first century, has only known four presidents. Aradesh the founder, his daughter Tandi who was constantly reelected till her death, the ineffective Wendel Peterson and the war hero Aaron Kimball. Many for good or ill, point the monarchic tradition it gives the state. Still compared to many states of the Wasteland, the Republic can boast faithfulness to the ideals of liberty and democracy. Even Super-Mutants and Ghouls are full citizens there. Still it doesn't keep it from being an expansionist empire under the current administration looking in all direction for more land and wealth. Yet it is starkly divided. Being one of the states with an active political life means NCR's society is torn apart by very different ideas on what they could be or even should be. Among some segments of the population, debates on the senate floor are heated enough to serve as radio entertainment.
Perhaps all in the eyes of the beholder. For some the Republic is groaning under its own weight, corrupt interests holding sway on many representatives. The powerful barons of the Big Circle who hold the food supply, caravans companies who fight to the death for control of the trade roads, even arms syndicates like the Van Graffs and the Gun Runners have all their say in NCR policy and many of the largest consortium dream themselves merchant princes without understanding the terms. The Republic won its war with the Brotherhood but at the price of nearly all its gold reserves which caused a financial crisis. It prints its own dollars but as they are backed by fiat, people still prefer the old bottlecaps of the Hub who are indexed on water, something especially true in the Mojave. There are many reasons to be wary of more expansion as the state is struggling to swallow what it has eaten already. Still rumors about Caesar's Legion and its advance westwards are excellent at riling people up. The values of the NCR lead it into a confrontation with the openly slaver state even as Caesar dream of a triumphant return to the land of its birth.
Political life in the NCR may seem simple now. The presidential party of Aaron Kimball supports expansion and support of the Mojave expedition. They sit a the right of the assemblies and are openly supportive of the caravan companies and arms consortiums even if they expect in exchange these groups to furbish the army in equipment. Their main opposition comes from senator Allgood of the Boneyard. The former Follower of Apocalypse, a group known both for its outspoken attachment to freedom and pacifistic tendencies. Allgood is both his name and an appropriate sobriquet for the man who mockingly declared "All must be good indeed so let's expand." He is not alone, in the dark rooms of the senate, mayor Hayes of Dayglow is also a common face. The man suffers from what wastelanders call Old World Blues, an attachment to Pre-War America. Still he is supported by intellectuals and people who want a resolution to the conflict with the Brotherhood of Steel. His promises of advancing NCR's technological level may win him the next election and both the reformist elders of the Brotherhood and surprisingly Robert House of New Vegas have already made overtures in this sense. They remain discreet however, they know their support may cost Hayes more than it brings.