Originally, I was working off of the idea that Iyasu V remained Emperor of Ethiopia thanks to German intervention. There were rumors that Iyasu (a real person, mind you) had converted to Islam. So I went from there. 

In this reboot, i've decreased the presence of his religiosity and did not pass it down to his kids. But in the original, they were more Islamic. Also in the original, India invaded Arabia for no reason and Persia and Ethiopia (the origins of the Pan-African Empire) occupied their respective regions to protect them. This has been dropped in the reboot because it was silly. So why did Persia and Ethiopia invade Arabia now? I chalked it up as aggressive expansion. It isn't as rational as it could be, but those conditions still need to exist even if the original reason isn't there.

As for the nature of the Pan-African Empire... it is complicated. The difference between this world and the real one is that here we are looking at a stronger Ethiopian state and weaker post-colonial African states.