Interesting thread. VIA has two engineers up front for its long distance trains (as does Amtrak it seems), but one will throw the switches and sort of act like the conductor. In exchange, there is no official "conductor" rather their are just onboard service staff - for sleepers, coach, diner etc. Problems? Their is a "Chief of onboard services" to handle issues. The onboard staff stays onboard throughout the journey, except for the Canadian - where the entire crew is switched out. So I would assume VIA gets some cost savings with this arrangement of onboard service crew (no assistant conductor, no hotel expenses for conductors etc.). Again, I think this model ONLY works for long distance trains.
Moreover, one attendant can handle up to three sleepers, although typically they handle just two. Amtrak has one attendant per sleeper. Granted VIA's heritage cars have less capacity per car, but when you throw two or three together under one attendant, it outweighs Amtrak's capacity. There's a monitor inside the "50 year old Heritage cars" that tells them if there's a passenger calling in what car.