We know there
are more moderate or even progressive Garleans in the Empire's ruling class, they call themselves the 'Populares' and were wanting to bring hostilities with other nations to a peaceful end (coexistance and independence for those nations wanting to be free of the Empire). It was this group that Maxima belonged to and was taking Alphinaud to meet with during ShB's storyline. Alas though, they're something of a minority in Garlemald and naturally Elidibus-as-Zenos conspired to ensure Maxima and Alphinaud never made it to their destination (shooting down their airship over the Burn).
Irony of ironies though, it was that act that not only brought Gaius back into the picture (and revealed the whole Black Rose project the Empire was working on behind the scenes), it also revealed the prescence of the ancient Allagan forcefield generators in the Burn, which Hein and the Domans realized could be reactivated to form an impenetrable defense barrier that would basically cut the Empire off from Othard (or rather Othard's western flank) and so reduce the risk of Imperial forces mounting a counterattack against Doma to retake the newly liberated country. So, the Empire actually made their job of conquest
harder with that one act of trying to strangle the Populares, so,
nice job fixing it villain?
Either way, there definetely are benign Garleans still in the Empire and actively working for the betterment of their country (even Gaius still regards himself as a patriotic Garlean, but is outright resisting the government and military he once served), but alas their numbers would be pretty low (especially as it seems Varis initated some kind of purge of the Populares so if there was any survivors still holding to that ideology, they would probably be in hiding within Garlemald). We'll probably find out either way.