Basically, (very bascially), they both idolise nature (especially in relation to childhood)--i.e they're pantheistic.
Malouf explores (in the setting of the outer bounds of the Roman Empire) the idea that, to discover your true self and bcome a complete person, we have to abandon the technology (which had supposedly made Rome so morally corrput). Wordsworth also uses this idea, within the context of the industrial revolution. Here, there is a need to return to the simple life, and escape the dirt and noise created by the industrial revolution.