Makhaya represents—or epitomizes—positive human actions because of his departure from South Africa. Remember, in South Africa, Makhaya was subject to brutal racism. He was in jail and he contemplated acts of violence, like bombing a power station. Rather than continue to try eking out an existence in such a destructive atmosphere, Makhaya moves to Golema Mmidi. Here, he hopes to straighten out his “jumble of chaotic discord.”
I think you could make the case that Head might be trying to encourage more humans to act like Makhaya. That is, don’t stay in a place if it is harming you. It’s better to move along and find an environment that can help you feel at peace. That’s what Makhaya appears to do.
It’s also what Gilbert seems to do. He goes to Golema Mmidi to help the village. As the narrator says, he’s there to “uplift the poor.” As with Makhaya, Gilbert is following his gut and trying to be helpful and useful—two qualities that you could argue epitomize Head’s ideal human.
Although, Gilbert’s race and class shouldn’t be ignored. You could make the claim that Gilbert's behavior is more of an epitome of less ideal human behavior. You could contend it links to the idea of “white man’s burden” and the racist assumption that white Westerners are best equipped to manage and organize non-white, non-Western societies.
As for Dinorego, he might contribute to Head’s epitome of a human being due to his decency, tranquility, and generosity. He invites Makhaya to stay with him. Makhaya tells him he’s “penniless.” Dinorego replies, “A poor person like me can still be hospitable.”