The difference between the success rates of the BACX pilots and other pilots is because of the fact that BACX pilots will be invited to interview, even when they have not passed the application screening process. It is as simple as that! If everybody who applied was given an interview the success (or lack of it) rates would be comparable.
It is not possible for me to comment on the outcome of a particular sim but I would like to say that sometimes "questions" are raised on day 1 that need to be answered on day 2!