While I think what you're proposing is the ideal, the question becomes, what are the tasks that can be reasonably done in e.g. a week? Would the average "good"

While I think what you're proposing is the ideal, the question becomes, what are the tasks that can be reasonably done in e.g. a week? Would the average "good" employee finish them in 20 hours? 30? 40? That's why I think there should be a guideline in the number of hours.