Not that this is relevant to the original discussion, but as someone who runs lots of games set in Cheliax, I can answer the Hellknight alignment question.
Hellknights do not serve Asmodeus. They serve The Law, a la Judge Dredd. They often take INSPIRATION from the discipline of the legions of Hell, but given that they specifically slay a devil in order to “graduate” their training, they certainly are not de facto allied with Hell. Moreover, some Hellknight orders are lapdogs to House Thrune, while others consider themselves to be an authority exceeding even that of Thrune (though these Hellknights rarely voice such opinions out loud if they want to avoid a sudden, unfortunate end).
Some Hellknights serve Asmodeus. Some serve other lawful gods. There’s an entire (main supplement) order of Hellknights called the Order of the Godclaw that picks and chooses aspects from five different lawful gods, including Asmodeus, Iomedae, Abadar, Irori, and Torag. This is not immersion-breaking lore–it’s literally been there since the beginning, when Hellknights were introduced.
I’ve done a lot of great politics with Hellknights in my games. Lawful Good Hellknights are rare, but always crunchy. Unless they happen to live in a more permissive city, like Kintargo, they do tend to meet bad ends more often than their fellows, though.