How much of that yellow does the YPG/Kurds keep/hold? Do you think?
Well, all the Kurdish areas are in the blue patch but
Realistically speaking, the YPG IS the SDF in large parts, and the PYD controls pretty much everything about the whole ordeal. They make up anywhere from like 30% to over 50% of the total numbers of the SDF, and the numbers of Arabs in the alliance have long been suspected to be exaggerated for political reasons.
I suspect the various Arab allies the PYD has gained will turn on them, with the possible exception of Jaysh al-Thuwar, an oldschool FSA group who allied with the YPG originally around 2013 (Groups that make up the merger group Jaysh al-Thuwar anyways), mostly due to their sour relations with the "green rebels" complete with old videos from Idlib where rebels brag about hunting down Jaysh al-Thuwar cells and some groups even wowing to behead any members they catch
The only real option they have is accepting whatever crumbs Assad is willing to throw at them, because they're fukked if this goes through. KRG is at full capacity, the IDP camps are already overflowing in SDF territory, and there is no system in place to accomodate for them in government-held areas either. A lot of lives will be ruined if the Turkish operation goes through sadly.