@Baldur
Of course! That's teamwork. The spikes would also defend against attacking Klyros.
Is this what you mean by the walls?

The cross is the window, because it allows an archer to move the bow many directions without leaving a big opening through which other things can get in. The bottom floor is filled in with rubble, and stairs are in the guard towers connected to the walls.
@Nikodemus
Your Ylian building inspired me to do a Kllyros take on the same building shape. Maybe this will help to compare architectural styles.

I did not have many windows because yes, I forgot. They were quick sketches.
I meant to fix the map, and I am confused as to what I forgot. Please compare:
Here are the main and landing platforms roads:

Green is the Main road and red is the Landing platforms road.
I colored the different sectors from dividing by the three roads:

I think it is possible, no fourth gate needed in my opinion.
I realize that the road is not a gentle curve. I have reasons for that. I believe some planning of the city (including roads) was involved, especially in the Landing platforms. Therefore, IMO the road would not be quite so directly curved, if you understand. Also, IMO while buildings are built to fit in the land and on roads, the layout design would not include places between roads that are so narrow that buildings cannot be realistically built. For the landing platforms road, I think it would need to go further into the landing platforms to effectively improve transportation between all parts of the city. The wall curves in by the landing platforms because the platforms are dangerous and noisy, IMO scaring away potential residents. The highlighted roads have some angles because I highlighted them with a straight line tool.
I agree with the tower levels. I realize that half of our time is gone. As soon as we agree on a city plan, I will start working on the underground layout. Thx for the comment.

@rast
I see you posted below me. Glad to know you're still here.

I agree about the questionable nature of spikes. They were just an idea.