I seriously doubt that when you said 'people from big 4 should pass ur requirement'. I honestly don't think so. I don't think it is that hard to get into big 4 considering the fact that audit firms are always lack of staff, and the high turnover rate. And people who wants to be in IB and has got what it takes to be in IB, he/she will apply for IB and get himself/herself the job there.