Actually, upon reflection, it sounds like the real solution here would be to display religion titles and to give realms more control over title customisation/awarding of honourary titles.
Perhaps you should be allowed to customise all the titles (with the various title systems available as default options), and to create and award one or two honourary titles per realm. That leaves realms the ability to do the customisation they want (e.g. calling Lurian Dukes "Kings") and the ability to award special honours (e.g. "Royal Daimon Slayer") without needing to use guilds as a work around.
