Asia dwarfs South Sudan: about 44,580,000 km² km² against 623,998 km² km². At true size Asia is about 71.4× larger — the whole of South Sudan fits into Asia roughly 71 times.
The old Mercator map treated both about equally (1× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
South Sudan fits 71× into Asia.