After rereading the link I posted, I agree with you. Sweden only gained Viborg with the Treaty of Nöteborg and Karjala with the Treaty of Stolbovo. So Karjala will start under Novgorod. City name will be Korela under Novgorod/Russia, then Kexholm once under Sweden. I plan to use persistent events to check ownership and change city names...Probably you are wrong. If you check the map at your link you will see that the Swedish part of Karelia according to Treaty of Nöteborg was Viborg (bigger part of Karelian Isthmus represented Viipuri province), while the rest of West Karelia remained part of Novgorod/Russia until the Treaty of Stolbovo.