Not sure if this has been addressed but ...
So, the Quyth Concordia was never conquered by the Creterakians. However, Quyth Warriors still have to go to the Combine to get cleared for upper tier ball.
So what happens when a Quyth Warrior goes to the Combine, and is found to have bio or cybernetic mods? Do the Creterakians still get to imprison or kill them? If that's the case then Quyth Warriors must have to sign some contract that releases their rights as a Quyth Citizen or something, and lets the Creterakians enforce their rules without causing an intergalactic military episode.