Afghanistan dwarfs Oceania: about 642,058 km² km² against 8,600,000 km² km². At true size Afghanistan is about 13.4× larger — the whole of Oceania fits into Afghanistan roughly 13 times.
The old Mercator map treated both about equally (1.5× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Afghanistan fits 13× into Oceania.