Just going to note the interesting juxaposition compared to real life.
In Real Life, the Byzantines are embattled constantly with Muslims, Pagans, and Heretics while the Catholic West captured one Orthodox base after another and converting them.
In SKNES the Catholic west are embattled constantly with Muslims, Pagans, and Heretics while the Orthodox West sought to capture Catholic bases and converting them, conveniently ignoring the Muslims (who are also ignoring them.)
In Real Life it was the Byzantines who roused the Catholics to fight the Muslims, and they succeeded. The Muslims were pushed back and they worked together for a while before economics made it fall apart.
In SKNES it was the Axumites who roused the Catholics to fight the Muslims. Meanwhile, the Byzantines are essentially protecting the Muslims by standing between the Catholics and their target.
This is not mentioning Hellenicism or other things, and focusing on the more weird "Nearly but not quite" events going on. The most weird *I* find is the lack of Muslim Raids into Anatolia, which were nearly ceaseless IRL. IN the same fashion, lack of inter-religious raiding over the Pyrenees (before official peace treaties), and the lack of intrareligious, and especially intersect, warfare.