Great War wasn't fought for decades lel. The Ottomans may have exited early, because IRL their beef during the war was mostly with Russians. They fought the British too but in PoW it's not clear for how long. After the Russians leave, it's likely they then focus their troops elsewhere and crush some of the rebellions and/or focus on the British. By then the British would not be in shape to fight in Anatolia since even IRL they had their fair share of setbacks. The Ottomans probably still got wrecked by rebellions and a long war, but Russia leaving probably helped them a bit.

As for Poland and Persian aid, that's iffy. This is a reboot and in this new canon Poland isn't powerful. The same may be true of Persia.

I'm on a phone and can't bitch to the fullest extent though so Imma just say Armenia stronk and the old canon doesn't matter.