"Not to be contrary, Lord Dumbledore, but it would overwork the OWL and NEWT testing subdepartments and both departments would be liable. Apart from that the OWL and NEWT testers were only able to make check-ups on the magical subjects, but wouldn’t be able to check the students in the muggle subjects since it isn’t their field and are not experienced. We need there everyone, who is experienced and had the needed qualifications.", Narcissa explained.