funny and wellinformed... I don't think there's any general ranking, though coordinated faculties like Law might have one.
I meant that each college will have a ranking for each subject, which used always to be included in the letter to schools, which they BY THE WAY still get though often without the ranking, so that you should be able if that's the only remaining option to use the Data Protection Act to find it out, or indeed to find out what the college told the school.
It's true that some administrators will discourage frank and free exchanges on the grounds that you might be about to launch a lawsuit, but this seems imbecilic, really. Very occasionally, too, you get someone who just never answers enquiries.
But I would suggest contacting in this order and until you have found out all there is to find a. the person who interviewed your child b. the other person who interviewed them c. the Senior Tutor of that college d. the Admissions Officer of the relevant faculty e. the Central Admissions Office, complaining about lack of feedback from all of the above and definitely mentioning it if your child is at a state school. (OTOH, a private school will often try all this for you... and some state schools will, but then they often refuse to share what they have found out with you...) Don't give up, and as with all enquiries, be patient, polite and willing to keep trying. Message me for more if you like.