Which factions do you wish would partner? I personally would like to see NCR integrate the Brotherhood as an autonomous client state, who would in turn join forces with the Followers & The Great Khans. This would lead to an absolutely unstoppable force in the Wasteland, and one that I would love to join.
there just two fractions i realy liked in the game and i would love to see them rule new vegas the followers would help citizens and make freeside less of a slums and the enclave will mantain order