Part of me is thinking they are actually connected to beastmen daily tribes.
Look at it this way, they could add an item at max rank for an FC to tame the primal and fight it
As if now beastmen dailies wise we have along with their respective primal
Amaljaa - ifrit
Kobold - titan
Sahagin - leviathan
And next patch tribe dailies is confirmed as ixali, who's with Garuda

Leaving one left the sylph and they've touted for ages that ramuh is coming.
So seems to match that for each respective daily tribe we would have a way to capture them