Final answer:
The Prime Minister of South Africa and the President of Nigeria are similar in their roles as governmental leaders; however, South Africa is actually led by a President. Both positions are typically involved in shaping their countries' policies and international relations.
Step-by-step explanation:
The Prime Minister of South Africa and the President of Nigeria share similarities in that they both serve as the head of the government in their respective countries. However, there seems to be a slight misconception in the question as South Africa has a President as its head of government and not a Prime Minister.
This position was famously held by Nelson Mandela, who, due to his leadership and anti-apartheid efforts, is often described as charismatic. Both leaders, in a general sense, are responsible for upholding the constitution, representing their nation on the global stage, and guiding their countries' policies and visions.