As RightDev said not perfect but normally good enough is to use the assign Rally Hex button then chose all formations button.
If players are setting up they need to be told to place its but if make as a scenerio can set as make it. PBEM is still possible players just play the scenerio as per normal.
Have played doing this with a deep defence as map can be longer than it is wide certainly on large maps didnt see any problems & use it the button in game normally for formations behind enemy lines to stop routing towards the enemy. Usually remember once someone has
