If you're really interested in seeing how individual schools compare, you need to go to their own websites and look at how the marks break down. It all depends in what you're interested in. Since most of the top performing schools are academically selective, you'd expect them all to do well. So the question (for many parents) is how well the brightest students are doing. Overall point score is pretty meaningless.
For example, Colyton Grammar (a school often mentioned on here, which appears at number 12 on that BBC table) seems to make a lot, if not all, of its pupils take General Studies. This bumps up the average point score for all pupils and hence the school's position, but you could argue is actually not at all helpful for the pupils themselves - only 8% of pupils got A for General Studies and 60% got B/C. So this exam may be distracting the pupils from their core studies and not giving them the grades that will really help at the top universities. And overall the A/A percentage was 24/32.
On the other hand, St Paul's, which appears way down the table, got 56% A* and 32% A at A-level this year. So although its average point score is lower (maybe on average they do fewer A-levels) pupils are getting better grades on the ones they do take - which presumably is more useful for them in university applications.
None of this really matters, as most people choose schools, if they even have a choice, for wider reasons than pure exam results. But it is interesting to see what different scoring systems give you.