The letter is clearly written by the city scribe, Druss.
Here is the list of Ideas I game up with, you asked me to put it in writing.
I submit these ideas, because as it is, the only real defenses the gates have, are from above. Any enemy who observes these defenses, could easily plan to avoid them. I beleive we must have more. Defenses that will be unnoticed by scouts. Defenses that cannot be planned for, and still effective even if the enemy does plan.
My first Idea, was some sort of enchanted item, inserted into the walls, or possible used as a throwing weapon, which will release an extremely bright light focussed outsid the gates. This will blind and/or stun any would be attackers.
My second idea, building on the first, would be to dig small tunnels, between the ramps down the hill, hidden from view of all going down until it is too late to defend themselves. These dug out paths, would not lead to sanctuary, but perhaps a small dug out room. These tunnels would be used by a small force, to come out after the enemy is blinded and helpless. When this wave is defeated, the force can retreat to the dug out room, and lock it, until the signal is given to come out again.
A third idea, also building on the above two, would be to use catapults to launch some sort of slipperly substance, aimed at the ramps, and areas above them. This would throw anyone attempting to charge the gates, off balance, possible making them fall. They would be vulnerable, not only to attacks from above, but from the small force mentioned above.
A fourth idea, was to create small, arrow-sized shafts in the wall, with concealed exit points. The enemy would be outside, and the archers could shoot through the walls, with no danger to themselves, and effectively eliminating the enemy.
Even if they avoid attacks from above, plan to avoid being blinded, and try to defend against the arrows coming from in front of them, I beleive this would be far more effective in stopping any attackers, and lower any posible casualty rates.
I have many more ideas, but I wish to discuss them in person. I know you are interested in my ideas, If your superiors feel the same way, I would like them to contact me, to speak about these, and my other ideas, In person.
Lerzon