[Starscream Gaga]

I think it's probably "Qilin" and "Kirinranger" rather then sticking to one because "Qilin"is generally accepted as the English translation for the beast which comes form the Chinese word which is pronounced "Ch'i-lin", while "Kirin" is a direct romanization of the Japanese word. I'm starting Dairanger today (yay) so I'm not sure if I'm correct, but I assume it's "Ryuranger" and "Dragon" rather then "Dragonranger" and "Dragon" or "Ryuranger" and "Ryu" and similarly with "Houhouranger" and "Phoenix", so it is keeping things consistent. The rangers keep the romanization of the Japanese pronunciation, while the mythical beasts get their accepted English names, which are all derived from Chinese mythology.

Also, "Kirin" in Japanese also means "Giraffe", so they could be avoiding people confusing the Qilin with a Giraffe too, I guess.