Oceania dwarfs Saudi Arabia: about 8,600,000 km² km² against 1,925,871 km² km². At true size Oceania is about 4.5× larger — the whole of Saudi Arabia fits into Oceania roughly 4 times.
The old Mercator map treated both about equally (1× vs 1.2× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Saudi Arabia fits 4× into Oceania.