tenpast - really, Don’t worry about schools with an “Oxbridge department.” We have had no advice re-college choice whatsoever. As far as I can see, the only “advice” these Oxbridge advisors give is to prevent clashes. For instance, DS is not able to apply to his first choice college as another boy is also applying there for the same subject. Do we are in our third choice now and all the guy said was “sounds good.” That’s it. Apart from that, they have no additional insight whatsoever - nothing you couldn’t glean yourself from a quick look at the stats. Maybe other schools give something extra, but ours doesn’t.
I think at least 80 odd apply most years from his school, but some if them are doing US applications too and a lot end end up there (increasingly so). Maybe about 30 actually go on average, but you can’t really read much into that because applying for something like engineering or medicine is a lot more competitive than other subjects and this will vary year to year. For some courses, getting into Imperial or LSE can be more competitive (in terms of numbers) than Oxbridge, for instance - it just might not feel as competitive to the student because there is no interview / extra admissions tests, etc.