He's hardly a Lunar poster boy, having been exiled and worships an ancestor cult.
You could even make him an Orlanthi chieftain from the empire, to important to martyr and exiled instead.
Or
Your players could go there intent on taking over the grant from within.
Sometimes exiles (Sartarites) just need to work to survive. Pay is Pay.
Where better to hide when plotting the Empire's demise...