There is some logic in Bando's choosing to name Sam Thoreau. Let us remember that Thoreau is an important figure in American Literary History, and he wrote a famous book, entitled Walden, which describes his decision to leave society and civilisation and live an isolated and secluded life in nature where he lives off of the labour of his own hands and eats on the whole only what he can grow or gather himself. Bando, as he comes to see how Sam is living his life and the parallels between his situation and that of Thoreau, therefore chooses a very apt name to describe the way that Sam has turned his back on civilisation and is dependent on nature for all of his needs.
I have included a link below to the enotes study guide section on Thoreau's work so that you can gain more information about it should you wish. It is a really fascinating work and a key text in American Romanticism.