Hope you'll forgive me butting in. I feel kinda guilty telling mapmakers what to do when I haven't made a map myself, but if you're willing to hear me out this might be an idea...
I've always thought CC should have a map of Istanbul, but it should take into account the incredible history of this city. I mean, this is not some 20th century shopping-mall shithole that can be described by chopping it up into districts. This is one of the most marvellous cities ever, a city that's been there for at least 2,700 years and for 1,000 of those years was the centre of the civilized world!
A map that would do it justice would include a lot of the magnificent architectural marvels: stuff like the Rumelian Castle, the Hagia Sophia, Leander's Tower, old Galata, the Walled Obelisk, and on and on and on. Oh God the list just builds itself! Anyway, each architectural marvel could be put on the map, and there would be an accumulation bonus for collecting them, say +1 for every two architectural marvels.
The marvels would be independent of the geographical districts, but could only be accessed through them. So, you would still have to capture the modern district of Kemal Pasa to access most of the old city wonders, and Kuloglu district to access the Galatian ones. Admittedly this would be somewhat unbalancing, and lead to really big battles for control of the centre. That might be okay, actually, but if you wanted to balance it you could pad the list with some of the less important forts and mosques in the outer neighbourhoods.
Anyway, just my humble opinion....
All that is gold does not glitter
Not all those who wander are lost
The old that is strong does not wither
Deep roots are not reached by the frost