What bothers me about fortifications is that no-one seems to have thought about digging bloody great ditches in front of walls to stop cheeky punters rolling rams up to the gates without too much bother.

I've also got to say I have no idea how to reliably kill siege equipment. If I use flaming arrows from four units of Ottoman Infantry on a single ram it still ends up reaching my gates. Fortress-guns cannot seem to deal with siege towers either (which is ridiculous...).

Is it possible to have artillery within the walls and fire indirectly over them, because the built-in artillery upgrades do not seem to up to the task?