There seems to be no rules as to whether the AI will work properly or not.
One of the consists on my route is a "push-pull", it runs half the time with the loco facing backwards, at the rear of the train, pushing the train. It seems to work just as well in this mode as it does when travelling normally. One exception, when in push-pull it doesn't stop in the right place at stations. The station (AJS Station 1x50s Invisible) seems to think the loco is a coach and the first coach is the loco.
I would agree with the advice "lots of trackmarks".
Mick Berg.