I would argue that having more hired staff on rotation would be more productive, even with fewer workdays by any one person. By having more people who have experience with a given task, should any one of them become unable to work, someone else can pick up the slack until things have returned to normal.

When a company relies on linchpin personnel, the loss of a person could be devastating, since the company will have to find a capable replacement to hire. That means interviews, introductory payment packages, hoping that delays don't cause further damage, establishing the new hire in the workplace, and so on.