I will say, the whole thing is very contrived, with quite a few potholes. Nevertheless, it;s a fantastic read, and although the 'science' behind it made we wince, it came up with a less flawed explanation than I would have guessed.
For me, the biggest issue is CCTV footage, everywhere, all from different companies, records of all they train journeys, expenses and everything. If this company were to exist it would need a near-country scaled capital and influence. Even then it's still unrealistic.
Would be much better if the just had the subjects move to a far away school, make them change their appearance enough, that when they return, the chances they would be discovered is basically 0. Since companies need to cut back on expenses as much as possible, the fact that they settle on such an over-assiduous remedy to cover... Also... that they use the same names as their adult names... that has be bothering me so much throughout this series. How difficult can it be to make up a first and last name?