There was conflict between African tribes prior to foreign influence.Africans and original native huemans were very in sync with each other until fairy recently due to foreign influence. And even if we all didn't use the exact same words or follow the exact same culture we all generally had a good outlook on each other. Inner fighting and warring amongst people over trivial things very often is a foreign concept
And the reason why it wasn't as intense as other nations isn't a product of inherent character but a product of geography/environment/resources and chance.