The Kimberly are doing their best to ensure someone from Australia makes landfall. Without melee units to protect, these cities are practically defenseless. Australia will need to use their airforce, and well, to damage these cities or cut through the endless array of empty carriers and subs. Although, amusingly, the Kimberly existing is causing a submarine with nuclear capabilities to be stranded off the coast of Amaravati. Well played Kimberly, well played.