I like the 'BOS' from 'Fallout 3' because they choose to help the people of the wasteland, other than just following orders and gathering and destroying the remaining tech.
Well, the Brotherhood was never about destroying tech.
That being said... I'm of two minds about the Brotherhood. On the one hand, MacNamarra is a lot more realistic in his goals than Lyons was... But I can't help but like Lyons because even though he's taken on an impossible job, he's done it for the right reasons, and I've always been fond of an interventionist Brotherhood ala Tactics.
I don't think the Lyons Brotherhood would fit in with this game; DC is a place for children, a place where the good guys are saints and the bad guys are clearly marked. The Mojave wasteland is a place for advlts. It's impossible to tell the bad guys from the good - Oh, sure, the Legion crucifies people, but they also make a very good argument as to why they do that. The NCR seems benevolent at first glance, but they're the same kind of nation state that led the world to ruin in the first place, and they're filled to the gills with corruption to boot. House says he has the best interests of New Vegas at heart... Yet he's obsessed with bringing back his pre-war wonderland. Yesman is a yes man, simply an enabler with no ability to decide whether a decision *should* be taken or not.
Heck, the Enclave is symbolic of this. In FO3, they were pretty clearly evil. Eden wanted a plan with no redeeming value, and Autumn was unnecessarily ruthless. In NV, we see the Enclave was composed of normal people, people who just want to do their jobs, people who disagree with the Enclave's aims and try to justify it to themselves why they're still helping the *E*. Just like real people.