I think that Azj-kahet's size is deceptive, because it's roofed in a way similar to the outer parts of Zaralek, it feels more closed off than it actually is. Like I said at the start of this observation, they focused all their screenshots on specific set pieces which makes it feel like zones are only one thing. Almost all of the Azj-kahet pictures are of that central nerubian city, but if you look at the few other ones:
That seems like it might be a pretty significant distance going straight back. The cave nature just makes it hard to tell because there's so few places (outside of Hallowfall) where you get a long straight view deep into a zone.
Especially curious if this thing is to scale:
Cause that's a whole lot of Hallowfall(?) and very little of the top two zones.