Guessing that the other 3 houses have the Agriches do their dirty work for them behind the scenes making them a necessary evil. Or magic. Who knows. ╮(￣▽￣)╭
Don't be naive it's not like the other houses are saint's either they probably just don't openly expose their dirty work like the Agriches do
they're too brutal and thats what makes them scary, maybe the other 3 doesn't want a bloodbath
Think about it. If they get rid of the Agriche's, what house would hold down the powerful and righteous Pedelians? The other houses might be using the Agriche's to hold down the Pedelian's, so that there would be a political balance. Idk this is just speculation.
Also, think about it. They haven't mentioned much about the other houses and it seems like the Agriche's influence in the dark might be difficult for them to get rid of, since they are hard to predict (& super strong).
I just don't get how the Agriches get away with all the atrocities they do. I mean there are four other powerful families, so why do they not ally and try to bring the Agriche down? And there should be at least some kind of government (at least a monarchy) because there are obviously no laws in this country