Based on the preface, what are the different biographies mentioned and how are they distinguished from one another?

The preface detailed in Chapter 0 outlines several important Guru biographies. It mentions two by Shri Dasganu Maharaj in his Bhaktalilamrut and Bhaktisaramrut, noting they are excellent but very short. It contrasts these with the work of Shri Annasaheb Dabholkar by pointing out that Dasganu Maharaj discussed national issues, while Dabholkar did not. The preface also describes a scholarly biography by Shri Samarth Sadguru Vasudevanand Saraswati Maharaj, which is considered less famous than the one by Shri Saraswati Gangadhar. Finally, it introduces the 'Laghu Guru Charitra,' an older work distinct from Saraswati Gangadhar's 'Brihad Guru Charitra.'