Yes, you are only missing Castanoth. I didn’t make any others just because nothing else came to mind.

Didn't Balgar make most of the fortresses in Cannor? Isn't that why they are called Bal whatever, Bal-Ourd for example? Maybe a monument in Silverforge since that's where his holy site is? The flavour text for the event does say Castanoth was just the basis of something else, I assume it was some kind of ecumenopolis inside the White Walls?

Yes, he did make all those fortresses but they are already represented in game so I can’t really do much with them. Silverforge is quite distant so the player will probably never reach it from kudghir. I thought about making a white walls upgrade and a railway for the castonath region but other projects took precedence