By that definition, there had only been one Sage in the history of his birth village. Every Sage he ever knew of had chosen their study, and gone to one of the sacred animals to learn senjutsu. It could be argued that those who were successful had the ability to harness natural energy all along, and simply didn't know how. Which might very well make Minoru the only Sage to truly choose his power.

"I was born into my fire affinity."