I’ve heard some mockingly claim Greeks are really Turkish because some Greeks and Turks look the same. They cluelessly don’t understand that’s because of some Greeks (Greek speaking Romans at the time) being assimilated into Turks! Any Turk that tried to convert to Christianity would have been executed. At least during the era of Ottoman rule it was impossible to be assimilated into a Christian of any ethnic background. The breakup happened because many across the Ottoman empire realized they would eventually be assimilated into Turkishness if they didn’t fight for their independence (exactly why the Kurds now fight)