The Heralds win easily. Surfer could easily take Superman thanks to his many weaknesses, such as draining him dry of his solar energy, hitting him with red sun radiation, or hitting him with a concentrated blast of Kryptonite. Morg could probably take down Supergirl as well, i couldnt see her standing up to his assaults, with a deadly combination of a nearly indestructable axe, massive strength, and huge power output. And Firelord would put down Power Girl. She's not really powerful enough to stand up to him for very long, though it wouldnt be that easy for Firelord either. But when it comes down to it, Morg and Firelord overwhelm Supergirl and Power Girl, and Surfer could beat Superman quickly thanks to his vulnerabilities.