The Crescent has been terminating/beginning in Atlanta the past few weeks while NS is working on track in Alabama (I believe). As a result, it is parked next to Peachtree Station for most of the day. I live nearby and have seen the Crescent parked (or rolling down the track in my backyard) several times over this period. All but once, the sleepers were in the rear. Not really sure the rhyme or reason behind when the put them in the rear/etc. Perhaps someone wiser can shed some light (as I am curious).
The rhyme & reason is to reduce switching in the Sunnyside yard in NY City during the winter months. Normally during the warmer months, the Lake Shore Limited consist doesn't interline with the other routes. Except for inspections & problems, the LSL's cars tend to remain on the LSL during the warmer months.
But when winter hits, Amtrak tries to send the LSL cars upon returning from Chicago on a run to the south to help thaw them out and avoid problems. Since the LSL's NY section runs with the sleepers on the rear of the train, necessary to reduce switching in Albany when the combine/separate things, Amtrak alters all the other single level trains to put the sleepers on the rear too. This cuts down on the need to switch cars around in Sunnyside yard to conform the normally front running sleepers on the other trains.
Amtrak wants to keep switching to a minimum, not only because it's harder on the crews in the cold weather, but also because it means cutting power to the consist and that can add to the freeze-up problems.
So again, by swapping things on the southern trains, it becomes very easy for Amtrak to trade consists between the LSL and the other trains and rotate the equipment around to help thaw things out.