http://www.youtube.com/watch?v=jMwuqq2JZkc
watching this made me remember of something I long wanted to bring to this forum.
Siege warfare in WIA, especially the French and Indian War scenario is strange. Look at the effect of artillery on a fort in america in the video at 5.10.
Wooden fort could never ever had supported a months long siege with canons involved. They were efficient against Coup de Main (commando) operation and infantry attacks, but canons destroyed them in a matter of hours. Could the presence of artillery automaticly force the fort to surrender at the end of the turn the canons arrived?