... by building safe and secure settlements that attract and keep settlers? It seems obvious to me that if it is working for the Minutemen, the other factions would be quick to try the same strategy. Raiders would set up something like Bartertown (Mad Max III). BoS would secure settlements from which they could draw new recruits. Institute would create propaganda outlets that look a lot like how West World was _supposed_ to function. ("See, people? The Institute isn't the bogeyman everyone fears. We're here to give you a better, safer life!") Supermutants... meh. Hard to get past a cerebral cortex that stops thinking past "Must SMASH things!" Still, I'm sure you get the idea.