Before they even start flying, all will have an extensive English language course, some for over a year. Lot's of training done in house before being sent away to flying schools, currently Oxford in UK followed by the US for flying, then back to Oxford for final exams and twin IR rating. Back to Dubai for more intensive fixed base sim, classroom and full motion sim before starting line training. This is a minimum of 120 sectors, sometimes up to 150 if needed.
Experience they may be short of, but for training and knowledge to fly a commercial airliner, they are not. It's a 3 year course, minimum. It's not a guaranteed pass. Those that fail to reach the standard are removed, some even as late as line training.
Harry