Somethings don't add up. The upward revised number of ISIL forces is 31000. They have no airforce and no air defence. Supposedly fighting them are the American Air Force plus more than 700 ADVISORS, the Iraqi army, the Iraqi militia, the Kurdish Beshmerga, Iranian elite Alqus forces, Hizbullah and the Syrian government forces and still those ragtag gangs are storming more towns in Syria on one side and threatening Baghdad on the other side. Is anybody seriously fighting them? I really doubt that.
It could be that they were taken off guard and are consolidating their forces, but there's also the international implications to consider, the Kurds for example would have a hard time moving in and taking out ISIS, I don't know the exact laws but we know that the Iraqi government will have some kind of agreement in regards to sovereignty with the U.S so pushing deep into government borders would mean pissing off the U.S and could be an act of war and so on, I expect that's what the other armies are having to deal with as well.
You have to take into account that there are a couple of countries and a whole mess of provinces, regions and political influence in this particular part of the world, this isn't all neat and organised like the Ukraine where there are clearly defined areas of conflict and so on, it's a mess.