Meh... maybe it will work in the game, but please don't quote me Justinian! He's the one who doomed the Eastern Empire. His armies ravaged Italy and actually created what's called the Dark Age (Italy was depopulated and culture totally destroyed, Rome the city, didn't recover until the Renaissance) and he bankrupted the Empire to do his conquering. In his quest to win support in Italy he increased persecutions on other christian sects like the Monophysites, who were the majority in Egypt, Palestine and Siria. They of course converted in mass when the Muslim Arabs came: Islam was more near their philosophy, but mostly they were freaking tired of being persecuted and they didn't have any love toward the high echelons of the Church and the Empire.
Shortly put, if he hadn't lived at all, history would have been very different and probably WAY better for the Eastern Empire.