Because I am starting a postgraduate course at Girton in October... I'm not quite seeing how those two things are incompatible?
I don't take part in recruitment activity for the firm I work for. I am aware from discussions with Partners that university is a factor used in recruitment (although the firm doesn't advertise itself as 'university blind' to begin with). The university I attended was mentioned at various stages in my recruitment process - although maybe this has changed since I went through.
My comment "It's difficult, if not impossible, to engage in a truly 'blind' exercise" does not say "decisions are/are not made university blind". Even if you scrub an applicant's university from their application, (1) their A-Levels will be indicative of the type of university they attend, and/or (2) their extra-curriculars will be indicative of the type of university they attend.
On point (1), I accept that it is not necessarily true that (i) all students, with, say, A*AA will attend an RG university, or (ii) that all universities which have A*AA entry requirements are in the RG (although, without undertaking further research, I suspect most are).
On point (2), where a student says they're part of the College [x] Club, it becomes clear that they're at a collegiate university, the majority of which (to my knowledge) are in the RG. The same is true for when a student says they volunteer with certain law clinics - there's a clear link to universities which won't be scrubbed out.
In any case - all of this applies to the firms in this bracket which do indeed apply 'university blind' recruitment. Of all of the firms in the bracket provided (MC/SC/US), only a fraction advertise that they apply university blind recruitment. Maybe others do so without advertising it; I wouldn't know.
It's well established that London firms recruit more heavily from RG universities (
https://www.chambersstudent.co.uk/where-to-start/newsletter/law-firms-preferred-universities). Sure, you can query how many applicants there are from non-RG vs RG universities, and that may skew the numbers. I don't have data on that, but would be keen to find out.
So then we're back to my comment: "It will be significantly more challenging to get a TC at the firms you mention without having gone to a RG university." I stand by this comment. When it comes down to it, if a student wants to get a TC at a MC/SC/US firm, my advice would always be to attend an RG university (and, ideally, Oxbridge or one of the universities in London which are well regarded). There are a few universities not in the RG which you do see at these firms (Bath, for eg), but, generally speaking, I stick by my advice.
I don't necessarily think this is the way things 'should' be, but from my experience and the data I've seen, it's the way it is.