I'm assuming that "rank" in this case is an abstract measure of how dependent Gensokyo is on said figure.
You don't "outrank" someone like Reimu. There is no objective measure of power or influence that puts Sanae over Reimu just by name. Sanae invokes the powers of Suwako and Kanako to perform miracles; even though she is partly a god by 'blood', she isn't a god, or even a half-god. Sanae's purpose is to link the everyday people with the gods that they normally could not visit by performing miracles and the likes. She is a shrine maiden in the sense that she protects the shrine that houses the gods and attempts to keep faith steady, but is also a wind priestess for her ability to channel these two gods. Her powers still hinge on the influence of the two, and because the Moriya Shrine does not house any other gods or spirits she cannot channel their abilities. Reimu has natural ability and is essentially depended upon by all of Gensokyo due to their lineage protecting the Great Hakurei Border (by the way, due to her lineage she pretty much "outranks" even Kanako and Suwako, who didn't even need to cross over for the sake of Gensokyo, but simply themselves). One of Reimu's abilities is to call upon and communicate with gods. All of them that reside in Gensokyo. Which is a lot. She does not require to bring faith to any of these gods because her powers are not dependent on them; unlike Sanae she does not channel them, she simply commands them to do things. Hakurei Shrine's god is a different story considering we don't know what it is, if there even is one besides word of mouth, and there may even be multiple. But since her powers don't depend on the gods she doesn't need them, nor does she really need to supply them faith. Which is why the faith is so low in the first place, but that's a different matter entirely.
