There are many critisisms levelled at Oxford some of which are fair and some of which are not. I have to say the quality of the ground school cannot, in my opinion, be faulted.
My course finished about a year ago and several self sponsored students achieved first time ground exam passes which exceeded the 'sponsored' results.
Oxford does not however (or at least did not at the time) screen self funded applicants for ability. But why should they? If you have the cash then it must be up to you to decide whether or not you have what it takes...
Khalifa, by the way, was the answer to 'who is sponsoring at the moment'. Fancy emigrating?