Be careful about assuming that any Uni's Law course can be judged purely on the basis of entrance grades, or that that is the way to choose a Law School.
All LLB Law degrees are moderated and accredited by the Law Society. This assures a professional standard. Remember that entrance grades are a) used by Unis to restrict/control applicant numbers, b) as a way of ensuring that they are not 'the Insurance choice' which makes it difficult to predict eventual student numbers and isnt good for 'image', c) as a form of marketing (ie. you are already making assumptions about 'quality' based on ABB or AAA).
Make sure you look at the course, check the specialisms of that Law School, look for any extras on offer (study abroad, optional language units, pro bono work etc etc)and decide if its a Uni where you will feel comfortable for 3 or 4 years of your life.