Boom. If your argument was a person you'd have just blown its brains out with a shotgun.
You are clearly an efinancialcareers noob, because most people who have enough experience of eFC know they frequently put out uni rankings on various finance related chit, and the rankings should always be taken with a Mount Kilimanjaro of salt because they rarely tie up to reality. From what I've gathered its because eFC use weird criteria in picking their samples (as Princepieman mentioned), and they also tend to pick from a skewed population.
Though the part where you shot your argument's brains out is when you mentioned linkedin rankings.
https://www.linkedin.com/edu/rankings/gb/undergraduate-investment-bankingThese rankings are more or less the definitive rankings for best UK unis for getting into IB. Linkedin has millions of users in the UK, and data has advantage of picking up job movers at all levels of experience, not just at graduate/student levels as eFC is focused on.
If eFC or any other website disagrees with this list - they're wrong. LSE & UCL are higher than Oxbridge because they have higher proportions as % of their student bodies going into IB than Oxbridge (LSE is pretty much a banker nursery and UCL also has a strong IB feeder class YoY)
So everything you think you know about the rankings right now is likely wrong.
You can now thank me for curing you of your ignorance....it's a good thing healthcare is free in the UK, or I might have to charge you