Botswana dwarfs Oceania: about 580,622 km² km² against 8,600,000 km² km². At true size Botswana is about 14.8× larger — the whole of Oceania fits into Botswana roughly 14 times.
The old Mercator map treated both about equally (1.2× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Botswana fits 14× into Oceania.