You're assumptions are based on the mythical man month.
If it takes a woman 9 months to produce a child, 2 women can give birth in 4 and a half months?
People provide skills to a team that are either valuable to the team, or they are not. If the person doesn't find a way to add value, the team can and should lower his compensation. Ignoring someone’s value to a team and affixing their compensation to irrelevant external parameters makes the team less productive and less competitive.