Oxford v Cambridge: how do applications balance out?

[FingernailNibbler]

Silly question. Because you can only apply to Oxford OR Cambridge, how do applications stay stable year on year, or are there sometimes swings in preference (and do they cause panics at the unis)?
Do things stay stable because of students' preferences for the city/campus/vibe/course structure and content?
Do students sometimes try to play the numbers game and apply to one despite personally preferring the other? But does that just ensure a swing the other way the following year?

I looked at stats for one subject for 2020 (not an ideal year to compare thanks to inflated final acceptance rates, but couldn't find stats for Oxford 2019 by course). The numbers are amazingly close.
*MML 2020
Cambridge *
378 applications / 193 offers / 187 acceptances
Oxford
406 applications / 177 acceptances *
*
If just 50 C applicants had chosen O instead, it would be very unbalanced:
C 328
O 456

How is the balance in other subjects?
How do sixth forms/ O and C manage this?
Do you think it will ever become possible to apply for both Oxford AND Cambridge?

@CinnamonJellyBeans

I just don't get the idea of "quirky genius" with grade 9s in only a few subjects. Some of you might call it "genius", I call it "kid who is not good at much stuff".

Given that most academic GCSEs are pretty formulaic in terms of how you get to each grade, if you're smart enough to get a grade 9 in your best subjects, you should be able to get 7s in the others, just by attending school and doing your homework.

It's been my privilege to come across a few 'quirky genius' types in my field including one with dyslexia who back in the bad old days couldn't even apply to Cambridge because they required a foreign language and he could barely scrape O-level English.

So yes, they exist, and it's good they're not automatically excluded nowadays.

(He leads a group in one of the Cambridge research institutes now, as it happens)

For those people interested in the statistics the numbers are out for Cambridge in terms of applications this year, offers and winter pool offers. I've just had a quick look with dd and it looks quite interesting. Many more applicants to some colleges (like the one she applied to) than usual but a large number of those that they pooled were taken by other colleges as well.