Answer:
They belonged to different and even opposing factions due to geography and time.
Step-by-step explanation:
A second-generation society is defined as one that emerged from a declining empire or from the borders of one and also adds different elements to the culture, religion, history, etc., due to the context.
Nubians are considered a second-generation society because they (or at least a part of them) were part of Egypt or even of a rival, the Kingdom Kush according to the time and geography, which made them take parts of both civilizations to develop their own.