The Western Survivor will side with Yes Man as he doesn't want any pesky authority ruining his home on the range, and wants the Mojave to be wild and free from any ruler. You can either choose to be a more honorable gunslinger or a no-good dishonorable bandit for your morality and personality. Moral Alignment - Neutral Good or Neutral Evil (your choice) It's a tough world out there, and only the strong survive.
If you're going for a dishonorable outlaw, then feel free to cooperate with thugs such as the powder hangers, and rob, steal, and kill anything you want.
If you're an honorable cowboy, then you'll want to help the genuine honest folk of the wasteland and take down vicious raiders. With the Home on the Range perk, you can sleep on any campfire, which is great for their drifting survivalist lifestyle. While they aren't a fan of the NCR or the 'civilized' Vegas, they like to stop in little desert towns like Goodsprings during their travels.
The Western Survivor is your good ol' rootin' tootin' revolver shootin' wasteland campin, Cowboy.