Who is it that declares Saruman greatest of the Five Istari? Gandalf? By what measure does he know this? Was he, in this one case, being humble? Regardless, Gandalf the White states, I think, that he is about the most dangerous being in Middle Earth except if one were brought before the Nine-fingered one. If Gandalf says that he is less that Sauron, and as the White is greater than Saruman, then Saruman is lesser than Sauron.
Not that Saruman lacked spunk
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