How many Wizards?

[The Might]

In one place actually Tolkien did wonder if Glorfindel was a wizard at one point.

Another brief discussion, headed 'Note on the landing of the Five Wizards and their functions and operations', arose from my father's consideration of the matter of Glorfindel, as is seen from the opening words: 'Was in fact Glorfindel one of them?' He observed that he was 'evidently never supposed to be when The Lord of the Rings was written', adding that there is no possibility that some of them were Eldar 'of the highest order of power', rather than Maiar.