OP, correct me if I’m wrong, but isn’t Epsom College one of the ‘softer’ options compared to some of the other schools in the area? It’s known for a more ‘rounded’ experience eg. lots of sports etc, rather then academics? Certainly, the ones who went there from my DC’s school in SW London were the ‘middle of the class’ ones who didn’t get into KCS, Hampton, etc.
Having said this, I think many independents have noticed a drop in Oxbridge offers. Oxbridge colleges now have widening participation targets - they are aiming for around 80% / 20% independent / state cohorts to match what is the national picture at 16-18.
I can only really speak for C, but if applying from the independent sector now, you are best applying to a college that already meets that quota. Where they already have 80% of applicants from the state sector (quite a few colleges now do) they will not need to squeeze out independent sector candidates to meet WP targets. Have a look at the stats snd you will see success rates for independent school applicants are higher at these colleges, than others where they only get about 60% of applicants from the state sector.
Also, everything is now contextual. If applying from the (selective) independent sector, top grades will be considered the bare minimum. You will have had to have done a LOT of ‘super-curricular’ on top to be equally considered next to someone with similar grades from the state sector who has done nothing ‘super-curricular.’ Also, tutors use the Cambridge pool now to top-up their WP numbers so if from an independent, you are highly unlikely to be pulled out the pool.
For instance, the London selective independent mine go to still gets about 20-30 in per year (out of 200), but, in terms of Cambridge, nobody ever is offered a place from the pool and this has markedly been the case now for some years. They all either get in directly to their chosen college or not at all. And they have all done absolutely loads over and above the curriculum and all have at least 2 A predictions as a bare minimum for humanities subjects (3 A for sciences). If you ‘only’ have 1 A* and two As, the school tell you not to waste your time applying. They also push the EPQ as this is now recommended by Cambridge (not sure about Oxford) if the school offers it.
Maybe EC have not yet caught up with advising pupils in how much extra they need to do to present a competitive application? It is a lot these days.