Al-bab is a waste of resource for us. We lost so many FSA rebels and soldiers and tanks because of it. Our main aim should be to take afrin, manbij etc. YPG areas
I agree that Afrin and Manbij serves much higher importance to any Türk then Al-Bab. Any Türk anyday would prefer to first get rid of YPG threat within its borders, over Daesh, since it's clear as daylight that many countries, especially western ones, are planning in forming an autonomous state in Nothern Syria (Rojava). But there is no such risk from Daesh, no country is officially supporting them, and any power knows the strength and influence of Daesh is fading away. Half of Mosul is gone from them, they lost most of their power in Nothern Syria, US coalition led YPG is steadily heading towards ar-Raqqah, And SAA fighting them in Deir-ez-Zoor.
However, Turkish initiative of fighting Daesh was rather a smart move. A great excuse to set foot on Syrian soils, and deploy all sorts of military personnel and equipments, succesfully utilizing our T-155 howitzers and more. The corridor cleanse operation (Eurphrates Shield) was begun, due to Daesh - however, our real aim is not really Daesh, it's as we always stated, the ones who moves west for Euphrates River, that's exactly why the name of the operation is Euphrates Shield.
What lies west for Euphrates is the YPG of Manbij. After the cleanse of al-Bab (Bzaa and Qabasin included) I guess shortly the real rat hunt will emerge.
Another importance of the Euphrates Shield against Daesh is, that FSA needed to earn credibility, as our allies repeatedly were arguing that the only effective force against Daesh is the "Kurds" (YPG) - hence all aid must go to the "Kurds" (YPG). And to justify their "Kurds" (YPG), they formed them under a new umbrella, a strategic tag was thus alligned, "SDF" (Syrian Democratic Forces). Though, Turkey is very well aware of all the 100 different tag these degenerates are using.