This seems like it could use a little tweaking to me. I have a stack of 3 leaders and 4 units with an aggressive posture. The main leader becomes inactive but I am able to take him out of the stack to continue the aggressive posture using his subordinate leaders. Removing leaders from stacks for this purpose does not ring true. Surely if the main leader in a stack becomes inactive all his subordinate leaders should also become inactive for that turn?
If Amherst decides to winter at a fort his subordinates should not be able to ignore this decision and press on with an attack.
Cheers, Chris