Saruman's Ring

[Tirinor]

Maia seem to be able to put power into objects which seem to amplify the power. The most obvious example of this is The One Ring, into which Sauron placed a great portion of his power and this partially accounts for why he is more powerful than other maia, including the Istari and Balrogs.

I've always thought that the power Sauron put into the ring was for focusing purposes, not as amplification. It's design was primarily to rule the other rings, find them, bind them, etc. Sauron's power for destruction came from an undermined world leadership enabled by the designs of the ring. He had a good plan, not more power. Sauron, with the ring, is 100% Sauron, not 110%.

I think that Sauron's superior power (to balrogs and wizards) was inherent. Although equal in regards to station, the maiar were unequal in degrees of wisdom, workmanship, etc. Just like how all Elves are equal, but not equally gifted, or even the Valar.

Sauron's advantage was also that he was functioning without restraints. The wizards were functioning under guidlines of restaint as mandated by the valar in UT. Plus, destruction is always easier than maintenance or creation.