Thanks for your reply folks...

The gist of it is that my assaulting forces will scale the wall,
then go to the gate, and then I would not get the announcement
of capturing the wall... I figured that I'd need a spy, but in all
reality, if my forces make it to the inside of the castle, they
should be able to throw open the gates...

You'd see how frustrating it is when you have a Horde army
trying to capture a Roman city with ALL THAT BOOTY!