Namibia dwarfs South America: about 824,750 km² km² against 17,840,000 km² km². At true size Namibia is about 21.6× larger — the whole of South America fits into Namibia roughly 21 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.
Namibia fits 21× into South America.