That map has been overtaken by events (it’s dated January)
The Kurds (YPG) swept across the Northern border area with Turkey this Summer, from Iraq pretty much to the Euphrates River near Kobane. They were only about 30-50 miles North of Raqaa back then, and have inched up since then.
They will likely make up the bulk of a ground force to assault Raqaa, but they want to have a bunch of Arabs with them, so it looks like a liberation, and not a Kurdish grab of a long time Arab city.
A few thousand Arabs have been cobbled together from 15 different groups, probably enough for the political requirement and as translators/PR folks, even if they are not fully combat effective.
The Kurds from Erbil in Iraq (HDP) have a force of about 4,000 (Rojava Bde) ready to participate (mostly Kurdish defectors from the Syrian Army), but the YPG is hesitant to let them into their area, as the two Kurdish groups also compete for political control as political parties.
They worked out their differences recently to jointly seize Sinjar, and the HDP got resupply through to the YPG earlier in the war when they were in real bad shape, and no one else would help. So there is a good chance that they will work out a deal to gang up on Raqaa.
Reports on twitter that ISIS is posting flyers that all men 14 and up in Raqaa have to register, so they may soon draft folks for the defense.