Technically, colour wise and in terms of personality, the agathian got all the aspects of the “good people” They got blue and gold coat, they look friendly and just, and always talk about duty and honour. Who will be against ?
Mason, are the very basic evil, with red and black coat, evil speech, nasty and vicious ways.
While the campaign behaviours are a bit similar (- burning village and field on both side ) Mason are a bit over the top when it’s come to killing and torturing people.
While we can say that Marrik is a power hungry fanatic, the Agatha king did build himself huge doms in his castle. He probably had to resort to extensive work of serfs to do so as well .