Beyond the story of Chand Patil, what ultimate reason does the scripture give for Sai Baba's incarnation and arrival in Shirdi?

The text from Chapter 39 of Sai Satcharitra provides a profound reason for Sai Baba's presence in Shirdi, going beyond the surface-level story of his arrival with a wedding party. It explicitly states that Chand Patil was 'merely an instrument.' The true purpose, as explained in this chapter, was that Sai took this incarnation and came to Shirdi 'of his own accord' out of a 'great concern for the upliftment of his devotees.' The scripture asks who else but Sai would uplift the dull-witted, the fallen, the poor, and the simple and faithful people who lacked formal vows or penance.