Scaramanga
Brickhead
You can't liberate a city that is still under original ownership so a city state that captures a city state or capital from the original owner has no choice but to raze, it can't keep it.Nonsense. The game could easily have been designed differently. In fact, it's quite simple. "If city state or original capital, liberate. Else, raze." There, I wrote the new "city state conquers a city" logic.
If a city state liberated a former city state or capital under foreign occupation then they would just be serving the city on a platter to someone else since it would be so weak.