In Part Three, the hobos that Montag meets aren't really hobos at all; they are a group of men, mainly former college professors, who had to flee the city because they are wanted by the authorities. One man, for example, says that he hit a fireman who came to burn his books and has been running ever since.
These men identify as famous authors or pieces of literature because that explains and defines their new purpose. They are book covers: men who have memorized a book so that, one day, it might be written down again for a new generation to read. When Montag joins them, he becomes the Book of Ecclesiastes because he has committed the text of this book (or most of it) to memory.
These men are, therefore, waiting for society to break down so that they can step forward and help to rebuild. They want to create a new society in which book-reading and learning are not prohibited. For them, the future is the focus. This explains why Montag immediately joins them.
The hobos are different because they are men commited to books and the knowledge contained within them. They have memorized sections of books to insure the information is not lost, and they plan to pass the information onto their children so it is not lost. They identify themselves by authors or pieces of literature because those are the things they have memorized. Each man is responsible to remember different texts so they are not lost. Montag himself begins to memorize Ecclesiastes at the very end of the novel.
The society of "Fahrenheit 451" written by Ray Bradbury is very different from our society.
In the novel, hiding books is forbidden because the government does not want individuals and wants to control the people. They have to be equal.
And there is the difference to the hobos, the group of men who live in the wilderness. This group reads books and keeps them in mind, before the members burn them.
They identify themselves as a part of literature because each one reads one book and learns it by heart to bring it to the next generations.The men do not want to lose the high values of literature because their aim is to change the society after the war.