the proper name would be stub yard and through yard or double ended yard.
in our modelling reality even stub yard takes considerable length so unless one has run in excess of 12-15 feet allocated specifically to yard module, i wouldn't even think about double ended. 6 car train will need 4 feet long arrival track, + ledder + lead track, so it adds up. and the OP mentioned 12 cars
if you plan everything right (sorry, can not find the full yard building guide at the moment) you will not be backing out. operations will be as follow:
* train will stop on arriving track.
* mainline power disconnects from the train and uses
runaround track to get to the ladder (and then to storage perhaps).
* switcher shunts cuts of cars to and between classification tracks and later assembles a train on one of the "departure" tracks.
* mainline power couples to the train and pulls it away from the station
with that, if your trackwork is good pushing cars should not be any problems. i always test my track work by running 6+ car train full speed in pulling and pushing configuration in both directions.