I am a medical consultant qualified in a different country which does not even appear in the league table and I don't look for where my doctor is qualified but how they are clinically trained after that.
Some of the foreign educated doctors are head and shoulders ahead of their UK trained peers when it comes to practical skills! The basic sciences which some universities are good at ( Oxbridge/ UCL/ Imperial etc.,) is not the be all and end all!
As far as medicine is concerned you need basic sciences to some extent, common sense ( a large dollop of it!!), ability to communicate ( lot of foreign trained doctors end up having GMC procedures against them because of this mainly) , empathy and ability to connect to your patient - are all equally important. I completely agree with the pp who said that you should have to ability to talk to your patient and get relevant information- I have had patients tell me things which I don't want to repeat anywhere which were the cause for their symptoms. I saw a patient on a stretcher last Friday but recognised that her husband was my patient as well ( seen him once few months ago) enquired about him - I could not help her but she was surprised that I recognised her husband and they were very happy when they left!
Any prospective medic may have all of the necessary attributes or find some of the other attributes difficult to achieve - medical universities make an effort to make sure that they have all of the necessary attributes but it is not a fail safe method.
I have sat through Oxbridge/ UCL/Imperial admission talks, have Dd who has just got into a London medical school (OP not interested in Oxbridge but only London universities) have a number of medics as my close friends with at least 13 children known to me who have gained admissions to Oxbridge/ London - Kings, / UCL/ Imperial, Birmingham / Cardiff/ Plymouth in the last 6-7 years but apart from two all of them ,including my own Dd,did only three A levels and were successful! Only one of them went to state comprehensive but the rest went to private school but this has not affected their application process.
I am involved in postgraduate training honesty don't care where any of my trainees primary qualification is from but am only interested in how they are performing at their job/ what they require to progress in their training
Dd chose medicine at the last minute so I have to learn a lot in a short span of time and there are some brilliant suggestions on MN- use the information wisely!
As far as our advice to Dd is concerned- we both ( DH is a surgeon) have said don't moan about the work you are expected to do after qualification, don't watch time - if it means you have to go on your off day to learn something do it, make sure that you respect everyone who works in the hospital and treat patients as you will treat your friend/ family.
Due to high competition and also where one chooses to do their degree (Dd would not look at any course more than 3 hours of travel!!/ two girls with exceptional academics would not do BMAT) most universities do end up with really brilliant students ,who do very well once they have gained admission.
OP- please take him to open days, write to the universities he is interested, see how he is doing in Physics and if it affects if performance drop it - better to gain a medical place even if it is not where he wants to go...
Medicine is a marathon and not a sprint - he will enjoy wherever he end up!
Good luck to your son..
Sorry, it is a long post and was in double mind if I have to post - hopefully someone will find it useful!