The topic of mixing African Cichlids with South American Cichlids is a frequent topic here and on many other fish boards. The answer is almost always the same monkey-see-monkey-do answer.
The fact is that they will coexist. The JD's will grow faster and larger than the Africans so you will need to consider that for future housing. Although JD's have a reputation for being agressive, the africans can easily hold their own while they are roughly the same size.