Most people who are doing 3 A2s rather than 4 aren't doing so because they "can't cope" with 4, but more because they want to prioritise the three subjects that are actually either required for them to get into university, or the ones which are most likely to get them the required grades. Yes, there are people who manage to come out with four or five A*s at A2, but they are most likely lacking in other areas (such as people skills, and general experience in a non-academic setting) as a result. You can only go so far in life until you need to work for things other than grades. Once you graduate from university, unless you go into further study, nothing you do will be assessed and recorded as a grade or percentage (with the exception of things such as driving tests or additional exams needed for certain jobs). The point of going to university is supposed to be to prepare you for getting a job in a chosen field, not trying to attain as many A*s as possible. The reason top universities have such high grade requirements for their courses is because they want people who are passionate about their chosen course, and getting high grades in the A-levels related to this course occurs a result. In what way is somebody doing A-levels in say three related subjects and an unnecessary unrelated subject more suited than somebody who is just simply doing three related subjects?