Barney plays the long game actually. He befriends the wealthy and becomes their trusted advisor. He slowly poisons them against everyone until they are all alone and then eventually take their own life.

Billy, you are such a joke...you know nothing of the suffering Barney can cause. Your unimaginative Luigi solutions just show you don't have the guts to do what it takes to destroy someone.

You're not going to shoot your way out of this problem, Rambo III.