To accurately categorize the types of government for the nations listed, we can assign the following:
- Kenya: Democracy (specifically, a unitary presidential constitutional republic)
- South Africa: Democracy (specifically, a parliamentary representative democratic republic)
- Nigeria: Democracy (specifically, a federal presidential republic)
- Equatorial Guinea: Authoritarian regime (a presidential republic with significant power held by the president)
Please let me know if you need further information or specific types of government labels!