As long as these titles are "loose," I'm all for it.
However, if they're rigid and the *only* person that can make the deck building topic is the deck builder and such, I don't think it's a great idea. What if the deck builder has something to do or a busy week and can't be online enough? Or if he goes out of town? What about any of the other positions? Ideally, everyone would be active enough to to do their jobs, but things come up. The vault organizer shouldn't be the only one with access to change the vault, nor should the salvager be the only one able to make salvage topics, etc.