well the basic ideea is u have alot of factions but no real fight betwen them except the end and and some rare cases

so u have points of interest : helios / black mountain / scrap yard / lake mead water stations ( there are none but u get ideea ) - maybe some could be changed

faction : super mutants , BoS , Legion , NCR , Securitrons , Boomers , Bright Followers ,

every faction would have a quest that makes them ready to assault and defend interest points and ally / or not with other factions - reputation with each would influence decisions

a back end story could be that in the first there could be on only NCR , Legion , and for the other factions would join to help one or the other side , or make separate factions and ally with other factions depending on how the courier decides to end the quest