Ah, so maybe part of the answer is that still doing 4 A levels is much more common than I thought, at least at the v academically selective schools. 4 A*s takes you to 224 (the average for Cambridge overall), and then a number doing 5 would take the average up higher for some of the subjects (ie 240 for Chemistry at Cambridge!!)
I thought that a lot of schools had reduced number of A levels down fairly soon after the latest changes (AS not counting towards A level), to 3, or perhaps more commonly, 'start with 4 and then drop one at the end of Yr 12 if you want'.
This is all fascinating! Just checked like another pp against one of Birmingham's courses and the average tariff points are also quite significantly above the standard offer.
Though interestingly, Nottingham have now pulled out of uifs - perhaps they have had a different experience, for whatever reason.
I admit it, I don't think the case against ucs is proven - it's the 'if firm' part which is perhaps more of an issue as it puts pressure on the student to accept that univ. rather than another 'higher ranking' one. But on the other hand it wouldn't make sense as a strategy for Birmingham to drop the 'if' because they would then get a much higher proportion of students who missed their predicted grades (broadly speaking - obviously more complicated than that!)