I colored the different sectors from dividing by the three roads:

I think it is possible, no fourth gate needed in my opinion.
A plan is plan, simple and the buildings are symbolic - squares, rectanges, triangles. That's undestable. At this point it is posible to shape everything as needed w/o problems. In reality buildings aren't squares at all (like it is in Hydlaa - it is unreal) (unless it is manhattan, lol) Old roads are curved and buildings are built along it, tight, right near each another. Buildings often end with sharp angle at one edge (lower than 90
o) near the crossroads or with angle > 90
o but < 180
o Look at old european cities on google maps.
Of course this doesn't exclude squarish buildings from presence, i'm only saying they should be only there where it really fits (warehouses and whatelse)
I think the city itself is at very advanced stage. It took a long time since another quarter was started outside city walls - As long as the time it took them to build 3m wide and 7m high walls (previously i said ~300 years). So they are really short with free space in the city.
Originally, I meant for the semicircles around the inside of the gate to mark off a sort of gate plaza (like in Hydlaa by Oja gate). But I think a depression in the wall would be more defendable.
The squares are still good with the new depresive gates.
thx for answering :)