Earlier quoted context omitted.
Why is your idea of an employee's value relative to who that employee is?
Mainly that people are good at different things so I wouldn't want to compare two people on only one task. I don't really see how that interjection is particularly relevant for the point I'm making though.
The point you made is that you think it's only a fair comparison if you can clone the same person. Which is simply false unless your determination of a person's value is dependent upon that person rather than upon their output.