I noticed your model of Dubrovnik, while beautiful, was inspired by walls built on a much later date.
Perhaps you should take more inspiration from this medieval depiction;
Konrad Grünenberg;
http://www.dubrovnik-travel.net/wp-c...enberg1468.jpg
Bernard von Breydenbach;
http://www.croatianhistory.net/gif/dbr.jpg
The most obvious change would be to add merlons on all towers and walls to make it look much more medieval.
The rest I leave to you because it would require much of your work to be undone.
Also, please note the Coat of Arms next to the city in both examples.
No, it's not Dalmatia.