bob,
I think you got it worng,
I would say that they do have specific minimum scores that you have to get.
So if there only 5 out of 350 that passed the minimums, only 5 will go to auh. I do Not think that they will take.. "best" 35 from london and "best" 35 from frankfurt, as "best" might be not the same % for different locations.
Theres one more scenario... If theres so many that passed their minimums, they will go from top and choose the number of people that they can invite to AUH.
I cant imagine this working any other way... They want the best so they can choose.