It seems to me that the commonly-expressed idea that Arab Sunni troops in some numbers are needed–AND CAN BE MADE AVAILABLE–to combat ISIS is a pipe-dream not thought through. For starters many of those Arab states are already pretty well involved in Yemen. But even more important the Shia-dominated Iraq government (and its main backer, the Iranians–who already have their own boots in both Iraq and Syria) will not accept foreign Sunni troops on its territory; neither will the Alawite-dominated Assad government. Do people expect those Arab Sunnis to fight Iraqi and Syrian forces to get at as ISIS? Moreover the Turks, for their part, are darn unlikely to want Arab troops based on their soil.
Besides which the Saudis and Gulfies have not exactly shown in the past that they can cut much mustard in serious ground fighting. With all that in mind consider this piece by George Petrolekas at the Globe and Mail online.