You misunderstood me. No modding involved...
I was just giving you a bad comparison with that province thing. My apologies. I understood you hence I told you about "-ian" which lets you take control of Byzantine and disband the navy. Anyway, happy gaming and here's the thread from early days that talks about switches in case you're unsure if your extension is correct, etc... https://forums.totalwar.org/vb/showthread.php?t=26511