Well I have SN in Sagittarius like OP claims, but in 12th house (tropical and sidereal systems)
Throughout my life, I have been encouraged to develop NN attributes, obviously in Gemini & 6th house. This NN area being in a house responsible for health, work and self improvement has now bought me to a position in life whereby consuming a healthy diet combined with regular physical exercise and streamlining my daily routine has provided me with long lasting benefits for quality of life.
This was facilitated by an inherited genetic condition which "steered", in other words, got me thinking (NN in Gemini combined with well placed Mercury) how I could go about dealing with this and to seek professional medical assistance towards achieving this goal, which ultimately created a plateau of fulfillment. I can't put it any clearer than that.
So, this "proves" to me how western astrology can work in your life, especially in regards to house placement of the moon's nodal axis.