ES thought of being able to put units on walls. But they ditched the idea for technical issues or maybe they just thought it wasn't important enough. But it's not a big deal for me. It would be neat, even garissoning units in walls would be cool, but I don't care, it keeps out melee units so I'm happy.
All I really care about is gates, I hate how you can't lock them anymore.
As for accuracy, you gripe and whine but if it was actually implemented you would hate it more than not having it. You'd be pretty pissed off if your army if 40 Ruyters, 40 Skirmishers and several cannons were defeated by a bunch of Pikeman because your cannons and Skirmishers couldn't hit them. It just causes too many problems, it would grossly unbalance ranged units compared to melee.
"I found no one ripe for many of my thoughts; the case of 'Zarathustra' proves that one can speak with the
utmost clearness, and yet not be heard by any one." - Friedrich Wilhelm Nietzsche
"The fearless are merely fearless. People who act in spite of their fear are truly brave."
Oprichniks are the best units in AoE3. Why? It's elementary, they're Horse-riding Russian Pirates, nothing beats Horse-riding Russian Pirates.