From a Sartarite Orlanthi perspective, the Sun Domers are those Solar mercenaries that live between Sartar and Volsaxiland. They fight as mercenaries, generally hold themselves aloof from most festivals, except to show up at the big Ernalda ceremonies. Some are friends, some are enemies, but generally we are neutral towards them. Trust them when they agree to do something for you, but don’t assume they will do the right thing unless they have already agreed to it (which usually means paying them).There’s a community of them way out in Prax. Like all things Praxian, life is harsh and so are the Praxian Sun Domers.
All of MOB’s commentary is focused on that weird community of them out in Prax. To be honest, the Praxian Sun Domers are kind of the Asterix and Obelix of Glorantha.
Are the Praxian Sun Domers, being descended from Second Age Sun Domers, more or less Dara Happan than the Sartarite Sun Domers? not Dara Happans at all. Their interaction with Dara Happan things is more of a cargo cult.
Is there a line of authority between the two Dun Domes? Each Sun Dome temple is independent and autonomous – see the original cult writeup in Cults of Prax. They have different secondary stories, different locations, sometimes some different friends and enemies, but all recognisably the same god.