It is not possible to marshal trains in the correct order using the automatic vehicle replacement facility. The problem is that any locomotive is automatically placed at the front of the train regardless of what order it is entered.
This is fine for the traditional trains but it does not enable the marshaling of trains such as the British Rail HST, this has two locomotives, one at the front and and another at the rear of the train. The locomotives are both placed at the front of the train by the vehicle replacement facility, even though the rear locomotive faces backwards.
Could this tool be modified so that trains are marshaled exactly the order as entered by the player; not sorted automatically by the game? Most players know what they are doing, they do not want to be treated as children by the game.