I could see a problem with your methodology where someone is "good with excel", gets to clean up all the shit execl problems, never gets to work on anything interesting, never gets to improve, or learn the C++, which he may be better at given 6 months of using it.
There's nothing stopping such a person from learning additional skills on their own. There's nothing stopping that person from them asking to prove that they do have these additional skills. There's nothing stopping that person from them proving that their new skills provide more value than their old skills. And if that doesn't work, and their new skills are truly valuable, then there's a very good chance that somebody else is willing to pay for those skills.
