^ All my assumptions were being incredibly generous to Harvard though. I tried to minimize the number of Harvard applicants (in actuality, I wouldn’t be surprised if half the class applied!) and maximize the number of ABs (some ABs may not be interested in pursuing a graduate degree in the UK).
At the end of the day, the real numbers are impossible to obtain but I think my analysis gives people a good idea of the relative success rates.
Your final point about choosing colleges based on a variety of factors is well taken.