update on this, two weeks ago I was at a career con thing and a Durham rep was there and I asked her if Durham had any policies regarding under-achieving students and she had no clue what I was going on about. I specifically asked her that because I go to a grammar school where the standard is very high, would I have an equal chance as my friend who with me, because he is a Lithuanian migrant that sat his GCSES in a very underachieving secondary school and got the best GCSEs in his school. Again, she said no, but understood what I was asking, and elaborated. Apparently, if GCSEs are used as a deciding factor between candidates, the performance factor was taken into account. And that's why, she said, do well in you're AS levels, have a good PS you shouldn't have too many problems.
I would interpret what she said here:
08vihe is hypothetically competing against a candidate with AAA in AS level, and AAA predictions. you're PS's are on the same standard. the other candidate gets the place.
However,
08vihe is hypothetically competing with another candidate with AAB predictions at A level, AAB at As level (same grades). Their PS is on the same standard. The other candidate achieved 3 A*s, 6 As one B at GCSE. However, taking into account 08vihe's secondary school, his/her's GCSE results level the playing field. The outcome is dependent on other factors.