The manager of the person who asked the question thinks that if you take data in form of pairs (X, Y), split them up, sort independently and combine again, you'll get better results. In fact, such operation obviously destroys the relationship X had to Y, so the result is meaningless.
Doesn't it also assume you'll have access to the correct answer in production as well? Is X the observation and Y the correct answer, as often indicated by that notation?
