I know they have passed exams etc and I am sure they are both technically competent but I'm sorry both are too young. He is still a teenager for pete's sake (and looks just like my 15-year old step-daughter's BF!)
For me 21 should be the minimum legal age for an ATPL and 8,000 hours minimum for Captain - or at the very least a combined total of 8,000 hours experience on the flightdeck.