It's worth mentioning that the names of many Far Eastern Hyur and Roegadyn NPCs in-game are actually found in the list of automatically-generated Raen names at character creation. Examples of this include Isse, Rasho, Kotokaze, and even Kaien and Hien—all are possible Raen forenames from the character creation randomiser.

(This also applies to some of the few Far Eastern family names we have heard of, such as Naeuri.)

From this, it seems like we can probably gather that the 'Raen' naming conventions are really conventions that can be applied to Hingan and Doman culture more generally.