I think all those numbers might be upped slightly with extra children, but certainly one of the joys of QM2 is that she carries so few passengers for her size, and definitely not twice the number of the Vistas.
I can certainly see the comical aspect of trying to persuade a couple of rather frail and perhaps slightly deaf passengers to return to their cabins, because they were half an hour early. They would be so pleased to stumble with their several pieces of hand luggage back towards the lifts, which are always crowded on the last morning, even, for some reason, the ones going up. It would be almost as much fun for the hard pressed staff, trying to persuade them, and causing even greater delays while the discussion took place.
I totlally agree it is cheating for people to come down early, and I also think most people don’t. But I don’t realistically see what can be done. Perhaps any one coming down more than 15 minutes early should be disembarked from the opposite side of the ship. That would show them. 🙂