Mozambique dwarfs Oceania: about 790,643 km² km² against 8,600,000 km² km². At true size Mozambique is about 10.9× larger — the whole of Oceania fits into Mozambique roughly 10 times.
The old Mercator map treated both about equally (1.1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Mozambique fits 10× into Oceania.