I'm asking this because I don't think enough organizations from 1 & 2 have died off yet. The only one I can think of off the top of my head is the Enclave. Of course it isn't 100% neccessary, but I think some groups would have a better story if they were killed. For me I'd choose the BoS, Caesar's Legion, Redding mining companies, Crimson Caravan, Gun Runners, and the White Legs. And the group I'd want to keep would be the Khans, I like the idea of them forming an empire.