Your right. Would have been more correct to say:
‘The vast majority her cadet colleagues that I have seen are average pilots, some are better than others – I’ve trained them in a former airline’.
As far I’m aware, all the cadets went to BACX after Sept 11. So if the ones that BACX got are representative of the rest, they are average; some are better than others - unless BA kept all the sky gods to themselves after Sept 11 and sent the duffers to BACX.