I generally favor the Brotherhood for their technology, and I mostly go for the Yes Man ending. I've done the NCR ending ONCE to see what kind of ending I'd get, and had the Brotherhood and NCR ally with each other then. I did two Mr. House playthroughs: One where I killed the Brotherhood and kept Veronica as a companion via an exploit, and another where I kept them alive and had House ally with them thanks to a mod that restores some cut content. The dialogue options are still in the game's files, just disabled in vanilla FNV. So far, I've never played a Legion-aligned character. Most of the time (including my first playthrough, any %), I went for the Independent Vegas ending and left the Brotherhood alive every time. Most of the time, I've booted McNamara thanks to The Chain That Binds. My current run, I kept him in charge because I plan to ally the Brotherhood and NCR between killing House and installing Yes Man. And the Brotherhood could also seize the opportunity to retake HELIOS One while the NCR and Legion are busy duking it out at Hoover Dam. I sure as hell made that a certainty by activating Archimedes AND powering the whole Mojave during That Lucky Old Sun to kill the NCR troopers, then went back later to kill the Legionaries occupying the plant, including that turncoat Fantastic. It's better he die by my tribal Courier's Fist of Rawr or a Holorifle blast to the head than on a Legion cross given that Caesar hates chems. The Brotherhood should be trusting with a tribal-originated genius Courier in charge of New Vegas knowing that she killed Elijah and the Van Graffs (while doing Heartache by the Number, well before joining the Brotherhood) while reuniting Veronica with her long-lost wife, Christine. My Courier, on the other hand, can use the Brotherhood's fear of the NCR to her advantage. Use them, or make them even more withdrawn. In my head-canon, she convinces McNamara to ally with the Followers of the Apocalypse and cut the hoarding shit for once. I've got some playthroughs under my belt where I did I Could Make You Care by finding the farming technology at Vault 22; you'd think McNamara would be all over that knowing that his Paladins can't fight if they're dead from starvation. Napoleon Bonaparte once said that an army marches on its stomach, and he was right.