Can you provide a list of Sadgurus mentioned in the preface and their specific caste and religion?

The preface to the Shri Sai Satcharita does not provide a list of specific Sadgurus. In fact, it makes a point to state that such worldly details are not important. As explained in the text from Chapter 0, the author establishes the principle that a Sadguru can belong to 'any caste, religion, age, is in person or in the form of a book.' The central focus is not on the Sadguru's identity in a worldly sense, but on the necessity of a Sadguru's grace for salvation. The text emphasizes serving them with faith and devotion, regardless of their background, to attain knowledge and spiritual liberation.