I have a question. Why does the Victorian Government resume land and the Commonwealth acquire land? Is it because the constitution states that the states resume land and the Commonwealth acquires it; the Crown is properly represented by the Commonwealth in matters relating to land or the power to hold all land is vested in the States as a residual power after the creation of the Commonwealth? I'd appreciate any clarity on this matter.
Without looking into it into much detail I think you will find that the land technically belongs to each of the states who Federated together to form the Commonwealth of Australia. Each of the state governments can take back land from the person occupying it by resuming it. If the Commonwealth wants to get land it has to acquire it because it never had it to start with. When the Commonwealth was brought into existence all the land belonged to the various states and they never gave it to the Commonwealth.
Technically no one owns the land they occupy, you have it as a form of tenancy from the government. In Queensland, for instance, you may hold it in fee simple, the full meaning of which will take longer than I have to spend on this answer, but essentially means that the only people who can take your land is the government.