There's also, of course, the people whose job it is. The people who have not been subverted by any evil, who are not in it for themselves, who are actually prepared to make meaningful sacrifices of their own joys for the good of the many, even to devote their life to that genuine good, regardless of the cost. In Golarion, people of this sort tend to get funneled into paladin orders or the churches of Good gods, and such people often find themselves at Lastwall, where they can devote their lives and afterlives to engaging in Lawful Good war against the forces of Evil. In Lastwall, government positions are offered to Good people who seem to have being good at these jobs, and if a lot of these are nobles rather than commoners, Lastwall would point out that nobles have received an unfair advantage in training and childhood nutrition from childhood, and that they are not in this to be equal, they are in this to win a war.
Now, someone from a world with rather less magic might think that all this would all end in a disaster, after perhaps; that people, aiming to be good not to do good would end up optimizing for signaling-goodness, and thereby fail to ever accomplish anything. And this would be a risk, even on Golarion! Except that the show is in fact run by Iomedae, Goddess of Defeating Evil, and the Lord Watcher of Lastwall is not actually chosen from among Her priests, because they are not professionals whose comparative advantage is choosing Lord Watchers of Lastwall - It's the generals who do that - it's Iomedae's priests are, rather, in charge of making sure that everyone in the hierarchy is focused on the job. So the claim that trying-to-be-good is having devastating consequences for Lastwall is, actually, false. What's having devastating consequences for Lastwall is that it set its taxes at the peak point of the Laffer curve when the Worldwound opened and they concluded that optimizing for maximum short-term revenue was necessary to stop the world being overrun by demons.
Or, in other words, Lastwall's actual problem is that there are so, so, so many threats. They were founded to keep the Whispering Tyrant under control, but the Whispering Tyrant happened to live next to the Hold of Belkzen when they trapped him in his fortress, so they also needed to serve as the shield of Avistan against the orcs of Belkzen (against whom they have lost ground), and then the Worldwound opened and guess whose job it is to stop that, and Hell conquered Cheliax from which they drew most of their membership, and -
Lastwall is generally just in crisis. Too many crises. It wants fewer crises.
What, then, are Lastwall's advantages?