It can be a challenge to view a
person who has always done a
certain set
of tasks or held one position in a different light, but you are doing your business a disservice not to create opportunities for
advancement for your strongest employees.
Since when did
people of the Bronze Age were ever less intelligent or developed than we are today other than
certain technological
advancements, which by the way not even everything technologically speaking is necessarily more advance today it was say two thousand, three thousand, or even four thousand years ago, so I have no idea where you get that reasoning from.