Beast Tribes: Are there strictly BETTER options?

[Rongway]

The only difference between the beast tribes is some are for combat jobs and some are for non-combat classes.

Combat: Amalj'aa, Sylphs, Kobolds, Sahagin, Vanu Vanu, Vath, Ananta, Kojin
Crafting: Ixal, Moogles, Namazu (4.3)
Gathering: Namazu (4.3)

The HW and SB quests will require you to do them on the job you accepted the quest with, and will scale to that job's level (up to the tribe's expansion's cap), but there won't be any differences in mechanics or set difficulty.