I think that George is constructed to be fundamentally different than the other men on the ranch because of his connection to Lennie. The other men on the ranch are able to fundamentally leave and be on their own. If they don't like what is there on the ranch, they can simply leave. This is brought out in the opening discussion of the ranch hand that had the bed before George and Lennie do. The basic timbre of life on the farm is a transitory one. Men come. Men go. George is not able to be that free because of his loyalty to Lennie. His compulsion to take care of Lennie makes him tied down, and not as free as the other men on the ranch. As a result, he is not entirely able to be as centered on self as the other men. He constantly has to make sure Lennie does the right thing, says the right thing, or at the very least, avoids saying the wrong thing. For George, his entire being is one in which he must be focused on Lennie and his own interests. In being unable to live a life of pure and absolute freedom, having to take care of another, it becomes clear that George is different from the other men on the farm.