Bit late but just come back to this thread.
Interesting selective posting from Xenia - here are Habs Girls' Science teachers' unis - you'll notice that they certainly did not all attend top unis, and one (Hatfield Uni, anyone?) went to an imaginary university! Which again, makes you wonder how carefully they've checked these lists and if the unis claimed are factual. (I used to teach at Hertfordshire Uni, which has a Hatfield campus - no such thing as Hatfield Uni, though. But apparently the person who graduated from there is unaware of this??).
Science
Mrs V Leigh, BSc London (Head of Biology)
Dr C Badger, MA Cambridge (Head of Chemistry)
Dr H Burgess, MA Cantab
Dr R Catchpole, BSc London, MSc, MBBS
Mrs J Dabby-Joory, BSc Southampton
Miss E Dinsey, BSc London
Mrs N Ghinn, BSc Nottingham
Mrs L Gupta, LLB Keele
Dr S Harnett, MA Oxon
Mr G Jervis, BSc Exeter, MA London
Miss R Lane, BA Cantab
Dr S Lindfield, BSc Liverpool
Mrs Z Makepeace-Welsh, MA Oxon
Mrs J McNally, BSc Hatfield, MRSC/CChem
Dr S Mirza, BSc Greenwich
Mrs D Moynihan, BSc Birmingham
Ms J Pan, BSc London
Miss N Percy, BSc Leeds (Head of Physics)
Mr E Stock, MPhys Oxon
Mrs M Walker, BSc Manchester
Interested to see your response, Xenia. By the way, for comparison, I checked my dd's staff list, and there are exactly the same number of science teachers - 20 - and exactly the same number - 5 - are Oxbridge graduates. The only difference is that none of her teachers went to fictional universities... And generally, the universities attended are 'superior', by your definitions.
I repeat, think your being done paying all that cash for nothing. I suppose you do get the nice RP accents, though. Which must be a nice consolation. Personally, I learned to swear like a trooper at grammar school, and my accent consciously moved downhill several notches. Can't say it's ever held me back though. :)