Tbh, I think that even those of us who went to Oxbridge ourselves or have other children or family members who got a place are still negotiating this for the first time in some sense. Things change all the time in the admissions process and even in the wider UCAS process and so even though I went to Oxford I actually don't have any extra helpful stuff to tell my daughter since a decades old experience of applying for Chemistry won't be at all helpful to my daughter who is applying now for English. Our young people are doing this for the first time and all we can do is support as best we can. Maybe helpful if you have an older child doing the same subject but apart from that past experience is not that relevant.
With respect to competitive courses etc, there is no value at all in assessing this. All Oxbridge applicants are bright young people who are doing their very best and whether they get a place or not they are doing so well just to give it a go and hope for the best.
Plus, honestly, a child who gets a place or even an interview for Maths or Medicine would likely struggle hugely with, say, Modern Languages or History and vice versa. It's not about which course is the best and most competitive to get onto or offers the most challenge. It's about if this is the right place and course for your child and if they will be happy and fulfilled there. I know when DD was picking universities to apply to it was really interesting to see how different some of the English courses were from one another. She is obsessed with Old English, having done a bit of Middle English at school, and desperate to do the whole Beowulf thing. Open days at other universities left her a bit disappointed that there was no opportunity to do anything like this. I hope she gets the chance but if she doesn't no doubt she will pick it up herself in some way. The whole reason she's applied to a university like this is that she actually loves learning and is really keen to take on the specific challenges of the course she's applied for. I'm sure your children are the same!
All Oxbridge degrees will be challenging for those who have the ability to take the opportunities offered. A child who is great at Physics would likely be unable to fully take up the opportunities offered in English just as an English student would not get the most out of a Physics course. People have different aptitudes and different abilities and that's fine. The world would be a very boring place if we were all the same.
I do agree that Sevillian comes across as having some kind of agenda. Perhaps this is unintentional. But it would be nice if this thread could remain supportive and kind.
Wishing all of our young people the best of luck and calm times in the days ahead. It's a tough process and all we can do is support them.
Sorry, v long!