"those who aren't familiar with European legacy carrier cadet training often seem to overlook that a) these cadets have passed a highly competitive selection and were selected for their ability b) these training departments often prefer to train pilots from scratch, to control every aspect of training and make sure cadets learn everything correctly from the beginning, rather than trying to fix bad habits those with more hours have already acquired (possibly in some pay-to-fly outfit)."
That's not quite accurate though - not all new EU F/O's have followed a strictly managed training path. They have a CPL/IR MCC and have successfully passed selection and completed a type-rating. Where they trained and how is not really given too much weight.