Tolkien himself also states Olorin and Curumo are of lesser Maiar than Sauron.
http://forum.barrowdowns.com/showpos...11&postcount=1
The only hope they had to match his power was with the One. I don't think anyone except maybe Galadriel could stand up to Sauron. I can't recall exactly but I think i remember her getting a lot of hype in The Silmarillion... Might be misremembering though. She was never a favorite.