Personally what I do for my Beast Tribe quests is do all the Kobold/Sahagin quests since even if I get a FATE there they tend to spawn quick. Then I'll split my quests between Sylph and Amaalj'aa depending on which tokens I need more of and which ones don't have a FATE that day.
Since you can get Bones and Shells easily enough with Allied Seals from Hunts, and bones are even easier since you can get those from Poetics, those two you can pick and choose from. Since Shells and Ore aren't purchasable with Hunt seals, you're better off getting them from the Beast tribes reliably every 4-5 days (depending on where you on with the cycle since you'll get 2 cycles of 5 days for 1 each then one cycle of 4 days for a 3rd). Then you get one every 6 days from the Vanu depending on which one you need more of at that point.