I've said before that two of the DLCs for New Vegas should have been legion territory and Shady Sands. I wanted to see the best that these factions could do, before I chose who gets to rule the world.

But alongside of those they could have added new factions. I think it would have been interesting to add the Water Merchants and, maybe, Caesar's daughter -- providing one more potential legion ending (I'm not the only one who wanted a little more legion content and depth I'm sure.) The water merchants are an economic powerhouse, able to dictate the currency that the NCR uses... that's significant. I can't even imagine a corporation making the US use something other than the dollar, but it shows the huge cracks in the NCR that this happened. (In Fallout 2, bottlecaps had become useless because of the NCR, but by New Vegas the water merchants had won the currency war again because of the brotherhood war.)

I can't remember whether or not I said this years ago, so I'll risk repeating it.
Both the west and east coast seem use bottlecaps as currency. Either it's an incredible, incredible coincidence that every town from DC to the Pitt to Boston all decided to use the same currency as the west, basically at random ... or, the water merchants have had contact with the east. People tend to view this as insanely controversial, but then I think that level of incredible coincidence is also a controversial choice. People often do wonder where the food (other than hunting) came from in DC. From... well, elsewhere off-map, I'd think.

Man, I wish the water merchants had been a major faction in fallout 3; maybe a representative of them had come along with the brotherhood. They'd see the water chip plan as a dire threat to a plan to control the water supply -- unless they had control of it instead of the neclave or brotherhood. It'd slot right into the game that was about a conflict over who was going to control the water and for what purpose.

IIRC only merchants and people outside the NCR and Legion are using bottlecaps. Both factions use their own respective currency (NCR dollars/paper money after the Brotherhood of Steel blew up their gold reserves and Legion Denarius).

You are right though that there are a ton of factions that could have been introduced in the game like the multiple New Reno gangs such as the Wright and Bishop families as well as the Yakuzas. I was disappointed that there are no representatives from the Shi. San Francisco was very interesting in Fallout 2 and would love to know what happened to them during the New Vegas timeline.

A trip to legion territory would also be awesome because they are portrayed as your generic bad guy except when you talk to Caesar himself. I always imagined legion territory as a mirror of Spartan culture who value marital prowess over technological achievements and of course slaves since Sparta had that too.

It's curious that obsidian didn't realize the importance of showing off the NCR and Legion towns. I'd put it as a higher priority than the DLCs that they ended up using.

For me, it was refreshing playing New Vegas initially as the Brotherhood and the Enclave were reduced to a more lore friendly founding principles version of both factions. As a result, they are a minor faction.

I would say that a majority of the people who played New Vegas when it first came out, it was the first time that the player had been introduced to the NCR and the Legion. I know the NCR were introduced earlier in the franchise but for a majority of new players this was fresh.

It's easy to look back and wonder, theorise and say that something would be better if done differently. New Vegas is an old game now, for as much as the community will forever keep the torch lit in terms of bringing the game into the modern era.

What I meant to say originaly was, the introduction of the NCR and the Legion are "Potential" factions as their success depends solely on the actions of the player character. In terms of any future Fallout titles that may come out, it would really depend on the setting of the game. As @Sirdanest ther are a plethera of small gangs and groups out there you could implement, expand or destroy in any future games and I tend to find these small groups more compelling as they can have their own identity without ruining the overall feel or artstyle of a game. The Kings are a great example of this, if you hate their artstyle then its okay because they play such a minor role, but the Railroad in 4 were shit and you had to see them all the time regardless of the fact that they were totally uninteresting. The NCR are a good example of a bigger faction done right, they feel like a government. They're spoken about as if they are so big and autonomous that they can't really be settled or reasoned with, they're too big for the played to take down alone.

I would have to agree with @ahyuser001 i think the SHI was a really cool faction that should have been explored in the NV timeline i would have liked them to have some presents in freeside. I would have liked to explore legion territorys abit more. But i guess thats a idea for modders to do

Yeah, completely leaving out the Shi was a bit odd, from the point of view of someone coming from fallout 2. Whether or not they were still an important presence in California could make a very big difference if the Legion invaded California, or if the NCR was benefiting from trade with the Shi. One more reason I had expected a California/Shady Sands dlc.

For my own curiosity...who are the Shi?