Was reading about how the end of the day for Byzantine soldiers was marked by the Trisagion - so looked it up from curiosity, the version they had couldn't have sounded too different. Beautiful, even if I feel uncomfortable listening to a Christian hymn.
Trisagion Hymn in Greek https://youtu.be/s4rMPzZHiiE via @YouTube
Another thing about Byzantine soldiers being religious; the Orthodox church doesn't give special permissions for killing for faith or Emperor, so Byzantines at war were doing some sort of low level penance (manuals of the time say keep it light so people still want to enlist).
So you can kinda see how an Emperor wanting troops he could easily assign to do whatever he wanted would like to have mercenaries who were Catholic, or before that, heathen.
