Thanks for mentioning Barzani Pehsmerga for Syria, I saw an article about that but didn't understand the full scope but now you confirmed my suspicions. People need to understand that Barzani can not allow the PKK to surround him or he will be gone.
I think if we cut down the Afrin canton we can end PKK corridor dreams forever. Now Assad has completed it for them, there are 10,000 PKK militants in Afrin, they can now be transferred to other areas of Syria for PKK operations.
I am of the opinion that we need to take raqqa because that effectively cuts off PKK from Assad and the Afrin canton permanently. If we only take Manbij and leave Raqqa for the PYD then they can still bypass Manbij and Al-Bab. Turkey also needs Raqqa as a launching point for FSA into Eastern Syria, trade routes need to be cleared to the rest of the Arab world. Turkey can't afford to let Assad and the PYD control our land routes to the Arab world.