Nobody has come up with (to my knowledge) a scenario where the Ottomans retain the Balkans but lose Syria, Iraq etc. and nobody has come with a 'Levantine Federation' where Israel, South Lebanon and Jordan are in a weird confederation.
Also, proposed nations like Al-Jazira (OTL Upper Mesopotamia) never make the list for Middle Eastern states, only *ethnic* ones.
Based on my take on the matter, it is assumed that it is easier for the Ottomans to lose the Balkans first because of the combination of three factors:
1) Extremely mountainous and rough geography that favors the defender over the attacker. When you can block 10,000 troops with 300 simply by placing all 300 in the appropriate spot, the ability to field more soldiers is no longer as important.
2) Very different religion and culture that makes assimilation difficult (not helped by the fact that this different religion is used as an excuse to justify the kidnapping of sons).
3) Borders with powers of religions similar or identical to those of the Balkans, which means a constant flow of weapons and resources to help the local populations rise up.
While Levante in return has:
1) Flat desert regions where whoever can deploy more troops wins, giving the Ottomans the upper hand. Besides that the geography favors the attacker over the defender.
2) Identical religion and similar cultures, plus the Ottoman can exploit his position as "leader of the Muslim world" to convince people to keep their heads down. In addition, of course, to being able to recruit them to oppress religious minorities (Armenians, Jews, Druze, Assyrians).
3) No relevant power is arming and supplying the locals to revolt, making it even more difficult for them to revolt.