Btw, to change the topic a little to be just a tiny bit more on-topic - it might have been fun to to try to model moving a division down a single track branch line with too few and too short sidings, a lack of proper turning wyes, not much in the way of spacious platforms for loading/unloading etc.
Add a few outages caused by raiders burning bridges and such like, supply officers always asking for more supplies than they needed (and then needing to move it forward or back, depending on how the battle went) and keeping the traffic flowing might became prove quite challenging :-)
Guess one pretty quickly would have had to reinvent at least some of Herman Haupt's principles (according to this web page I just found: http://www-cgsc.army.mil/carl/resources/csi/gabel4/gabel4.asp ) :
1) No military officers were to interfere in the running of trains.
2) Supplies would be sent forward only as needed.
3) Trains reaching the front were to be unloaded immediately by anyone available. Officers who refused to cooperate faced dismissal.
4) Where telegraph communications were unavailable, trains would run according to a rigid schedule. All trains departed on schedule, fully loaded or not. Extra trains would pick up the slack.
5) On lines where the absence of sidings prevented opposing trains from passing each other, convoys of five or six trains would travel as a group. Each convoy delivered its cargo and returned to base before the next convoy started out.