There is good argument for having at least 2 levels of control. There are many commercial applications configured for either of these scenarios (one could easily include all 3):

• AvailabilityManager:Scheduled
• AvailabilityManager:OptimumStart

or

• AvailabilityManager:Scheduled
• AvailabilityManager:NightCycle

How often these are used in combination is a great question for the community.