When creating attacks, it's hard to know in some cases exactly how many of each troop you will have home/available. For example, if you sent a nuke at a village and expect part of it to live and you want to use that as soon as it returns.
It would be very useful to have a checkbox by each unit type in each attack you create in SArmy which when checked it will send all troops that of that type that are in the village at the time of launch.