Want to do medicine, but have a huge problem. NEED HELP

how will they know what other students in my college got ?
that surely doesnt make sense to me ..I think there must be some other reason.why will they be so generous ?they have plenty of students applying for medicine then why will they do that
what i personally feel is that they might prioritise something else more than the grades or if something else in the application compensates it, they lower the grades.I am not sure of it but i have a feeling that this is the case.

The school can send the university details of how their students perform to strengthen the application of an over achieving candidate. A medical school will do it so as to widen access to those from "weaker schools" and possibly a poorer financial background. Medical Schools are concerned about making sure a variety of people apply, rather than saying it doesn't matter because there are "lots of applicants" (all of whom may be from very similar backgrounds). I know St Georges do it, not sure where else though. Other Med Schools may have different ways of "widening access".