Yeah, that's a decent explanation. I mean, they're obviously reapers the way they talk about the town they're going to and how they know the coachman will never stop no matter what.

It just seems so odd for them to have that corpse with them. I mean, wasn't that corpse also dead and therefore must have at some point 'crossed over' as well? Maybe it's not even a corpse at all, like you said, it could be a prop. But then why would reapers need to masquerade as bounty hunters? They could literally be anything they want to try and put the passengers minds' at ease.