Rojava Forces: Cizîrê Canton, with size, locations and roles. Hêzên Xwe Parastinê (thats the static infantry that includes conscripts) is significantly larger than I thought. It is interesting to note that there is a separate Syriac Christian police force--Sutoro("Security"), but not a separate police for Arabs--only the Asayish. Also, note the acknowledgement of 200 HPG (PKK) in the ranks of the YPG.
There are Arabs in the Asayish, some of whom were killed defending Khabur. Arab Asayish martyrs of the #Khabur resistance
Arab participation/alliance with Tev-Dem/YPG
Syrian Kurds Appoint Arab Governor
Al-Shammar leader threatened by ISIL for cooperation with Syria Kurds, June 8, 2014
There are Shammar in the YPG and YPJ in addition to Liwa Ahrar al-Jazira (LAJ).
Arab youth in the front line with YPG and YPJ, August 8, 2014
"Liwa Ahrar al-Jazira disbanded. Also, it was Shammar tribal militia. Their fighters than formed Karama army, which is now known as Sanadid army."
"Sanadid deployed large force in Tal Hamis battle and are in charge of security of Shammar areas, also jointly control Til Kocer border town"
"Also, not all Shammar are pro-YPG, it's mostly the historically dominant al-Jarba branch, who were the ones supporting YPG. During the February Tel Hamis offensive, loads of Shammaris from al-Faddagha branch were killed fighting for IS against their al-Jarba kinsmen and YPG."
Reddit discussion on the Arab tribes working with the YPG
Zubayd support YPG.
The Battle for Syrias Al Hasakah Province, October 24, 2013
Jawala, Sharabi (Sharabiya), Benitaba and Rashid
YPG Spokesman Redur Xelil: Liberation of Tal Hamis is a Very Strategic Gain, March 1, 2015
New group of Sanadid forces completes trainings, March 15, 2015
Video: Arabic Senadid Forces Speak about YPG Cooperation, February 28, 2015
Kurdish forces cooperate with FSA to free Arab villages from ISIS, February 15, 2015
Kurds bid farewell to Arab fighters killed in anti-ISIS battles northern Syria, March 19, 2015
Syrian Kurds and Arabs unified against ISIL. September 29, 2014
Kurdish Strategy Towards Ethnically-Mixed Areas in the Syrian Conflict, Publication: Terrorism Monitor Volume: 11 Issue: 23, December 13, 2013