Please let me reassure you that the head of Nonsuch is so obsessed with not
pushing medicine applications over other subjects that I swear I will scream if I hear him say once more that there is more to life than medicine and Oxbridge. He constantly stresses that girls should be picking the gcse subjects and A levels that they enjoy and want to study and not the subjects that their parents think are most academic. If anyone is obsessed about medicine and Oxbridge, it is the parents of the girls.
Nonsuch has also put in place several initiatives to address the perceived lack of pastoral care, which in my experience (two DD having gone to the school with one still there) was actually unwarranted in the first place. However, that is just my experience and others may feel otherwise.
As for higher intelligence girls going to Wallington, well who knows and really, it's not something I think you should lose sleep over. How your own daughter does will depend mostly on how much effort she puts in, not how intelligent the other girls are. The school isn't perfect (what school is?) but we have certainly been very happy with it and my DDs have been happy and have achieved very well