Not going into details, but why do you insist that the Napoleonic Wars or WW2 still happen?
That just creates the impression all you really want is "have Byzantines with tanks".
Then writing alternate history might not be the right thing for you.
No offense, but what you do is rather copy/paste history. Take WW2, cut France out, paste Burgundy in; cut Turkey out, paste Byzantium in; cut Hitler out, put different-person-but-still-Hitler in.
The only reason to create alternate history is to show how pivotal some decisions or events were. Here everything roughly happens the same way as in history, plus a Mary Sue Byzantium. It's almost like there's an advertisement screaming "Now! OTL! With even more BYZANTIUM!".
the Eastern orthodox church did not interact too much, perferring to do things itself before needing help. and this massive army of 50,000 only works circa 1025. its not that anymore, so its a lot less regulars, but still well equipped. they obviously refused to seek reunification, since the population was hostile towards it.
i was once told that even a tiny PoD could affect the entire world.
that independent Greece came into being when Macedonia got the tar beaten out by Byzantium. the reason for this is that Macedonia wanted Byzantine land, and Byzantium wanted Macedonian land.
there is support for a pan-greek movement, but Greece was under macedonian rule for 519 years, and they won back their independence. they did not want to give it up.
They already made a great deal of profit by having the silk route open. So they'd need a very good reason to suddenly decide to close it.well Byzantium could close the silk road anyway. although i cant imagine why. they have the capability to make silk natively, so it *might* be a way to increase profits.
So wait, are the Macedonians are ethnically distinct from the Greeks in your timeline, or are you using Macedonian to simply refer to the native Greek government? I seem to be confused here with the introduction of a third set of Greeks.
It seems strange to me, since the Roman Empire is ethnically Greek by this point, that Macedonians/Greeks would secede from the government. Being the Greeks are in power, I would expect rebellions from the Turkish population, especially those who are Muslim and are living in territory reconquered by the Romans. What is making the people in this area so unhappy?
the macedonians were ethnically distict by that point, unless Macedonia is really just a greek nation.
the turkish peoples did not care to rebel against the state which treats the Muslim turks pretty well.
1277: in the largest battle in the known world at the time 500,000 Byzantine soldiers face 100,000 mongols at Ankara. the Mongols decided to charge at the Byzantines, which were repulsed. then the Byzantines committed their own Calvary to hit and run on the mongol forces. a small Byzantine army of 50,000 ambushed them from the sides and behind when the main force started attacking. the battle is won, with 146,000 Byzantine deaths and 95,000 mongols deaths
This kind of stuck in my mind:
Is it really necessary to have such a huge disparity of numbers and casualties to envision a decisive victory in 1277 over the Mongols ? If an army of 50,000 seems big, this is titanic, and must have included a high proportion of poorly armed militia who would be more useful defending the walled cities of the empire.