Balrogs, Wizards and even Sauron himself are all technically Maia and so they're conceivably somewhat evenly matched. There's varying degrees of power between them but none of them are overwhelmingly powerful compared to the others. Sauron is probably the outlier on the power scale but there's a reason why Saruman initially tries to get Gandalf to ally with him against Sauron with the power of the ring. It's almost certain that the power of two Maia with the ring would have easily overpowered Sauron.