TheChosen1
Moving Target
The Overseer was trying to do his job of making sure people stay in the Vault until it's meant to open, not because he thought everyone in the wasteland was a bloodthirsty savage (or a mutant that needed to be put down)Remeber the Overseer threw the Vault Dveller out as he thought he was 'tainted' by the wasteland and would be a bad influence to the other people in the vault.
I could imagine that there are at least some people willing to join the Enclave as long as they have no conection with the wasteland.
Besides, the Enclave was not only about propaganda but their members actually believed to be superior and pure compared to anyone else outside the Enclave. Some Vault Dwellers could actually adobt that view point as well, seeing themselfs as the children of the survivors and the people that will one day create a new world after the apocalypse.
And yes, I agree that it's not all about brainwashing, but I seriously doubt an outsider, even one sheltered from the outside for so long, would be quick to adopt such extreme ideals. Did someone fill a Vault with USA-ified literature or something?
I'd be down with it if the scenario allowed you to have options, but I still can't imagine the Enclave sending someone out with the very real possibility of the agent going rogue. They might have their unshakeable ideals, but they aren't stupid enough not to think outsiders might show the "mutants" compassion. Especially when the mutants look exactly like humans.
I won't even go into the limited character interaction a game like that would have. Either leaving the player with an entirely combat-base experience, or a story of being sent as a spy to retrieve some vital info/mcguffin from somewhere, making low intelligence/charisma/speech builds implausible. (EDIT: Thinking over this point again, it might make for an amusing story if they just booted your retarded character into the wastes, giving you some menial task and hoping you never come back)
Obviously, the problem comes directly from the organization being intended as a one-shot group of villains rather than something with any depth.