No Silmarillion, os Balrogs lutam ao lado de orcs em muitos lugares. Poderia ser apenas eles eram aliados naturais.
Um comentário anterior sobre orcs escondidos parece ter esquecido que os Orcs estavam na mesma câmara que os Balrogs durante o ataque à câmara de mazarbul. Os orcs estavam com medo, mas não se esconderam nem fugiram.At last, in the year when Eärendil was seven years old, Morgoth was ready, and he loosed upon Gondolin his Balrogs, and his Orcs, and his wolves; and with them came dragons of the brood of Glaurung, and they were become now many and terrible. The host of Morgoth came over the northern hills where the height was greatest and the watch least vigilant, and it came at night upon a time of festival, when all the people of Gondolin were upon the walls to await the rising sun, and sing their songs at its uplifting; for the morrow was the great feast that they named the Gates of Summer.
‘As I stood there I could hear orc- voices on the other side: at any moment I thought they would burst it open. I could not hear what was said; they seemed to be talking in their own hideous language. All I caught was ghâsh: that is “fire”. Then something came into the chamber – I felt it through the door, and the orcs themselves were afraid and fell silent. It laid hold of the iron ring, and then it perceived me and my spell.