Since Kanaya's player planet was the Land of Rays and Frogs and Jade's player planet was the Land of Frost and Frogs, we can conclude that all Rustbloods would have lands ending with 'Melody', Bronzebloods would have lands ending with 'Zephyr' and so on, right?

Not really, Frogs is related to Space as a necessary Game Mechanic, but other than that the rest of the Lands relate specifically to a mixture of the Classpects and the Individuals, making all of them unique.