A driver in cab 1 goes into the first car of a unit and one in cab 2 into the
last - the ET42-A has only cab 1, the ET42-B only cab 2. The crew is the
unit's: the card, the details and replacing a vehicle all set it there,
rather than in whichever car happened to be selected.
The locomotive put first takes the driver, in cab A; the one it pushed
behind is left unstaffed. Stepping a card left or right is now an ordinary
move, so it also recouples the train and frees the coupler at its back.
Randomising flipped only the card's flag, so a multi-car unit was exported
with its cars in reverse order but each still facing forward - coupled back
to front. A swap copied the flag without turning the new cars. Both now turn
flag, cars and order together, as Flip does, and a locked unit as one.
The crew was copied to the card but not to the new cars, which are what is
shown and exported, so a swapped locomotive came out unstaffed. Swapping now
moves the crew over and otherwise staffs the vehicle as adding would.
