Regarding "Stronghold Crusader", I just wanted to add that
putting units on walls is what makes that game great, as it makes it a very tactical game.
This is a feature that is missing from AOE 3, and could make the game even better.
The greatness of that feature is that it gives the defenders an advantage, so all these players that like the
"Rush" method and win within the first 10 minutes, well that does not work in that kind of game.
In order to win you have to build a big army and only then you can attack.
But in a game like this even a big army is not enough because you have to be smart in the way you attack the stronghold.
Sending 500 units to attack by themselves won't you do any going, because 70 archers can kill all of them in a matter of minutes while your units are trying to take down the wall.
In a game like this you have to send your artillery first and knock down a section of the wall before you send your troops through the opening.
But even that is not so easy because the defenders also have artillery of their own.
I really think that by putting units on walls or at least behind walls (that give them extra protection) can make AOE 3 a very interesting game.
I just hope that Ensemble is listening.