What if the Devs added another "Clan" for each Race?

[Jandor]

Actually no. If they are actually a Garlean, with the third eye, they have 0 ability to manipulate aether. There are however a lot of Hyurs in the empire who are not of the Garlean ancestry, which is how they have casters at all. Strangely there are some Hyurs with Garlean ancestry, they are unable to use aether, and have no visible third eye.

The Lorebook describes it as:

"Garleans have little inborn ability to manipulate their body's aether, however, and thus the arcane arts have ever eluded all but a few."

It is rare, but not unheard of, for members of the Garlean race to be able to use magic.