Payments based on hourly rate and number of hours done for already completed work seem far more reasonable and secure for the DAO, in my view. They also give opportunity for multiple people to offer to do the needed work, which supports decentralization and avoids single points of failure. 

For example, a person does some amount of work and then they put in a proposal for the work they have done to be paid. They describe how many hours the work took and what their hourly rate is. The risk for the person is minimized since the DAO would be very happy to provide the payment so that the person will want to continue providing their valuable work. 

There is a vast opportunity which will sadly be lost if you think of a DAO as a typical company that is putting people on a payroll. The DAO allows for massive flexibility. Let's use the technology's possibilities. 

This still allows anyone to be engaged full time. They'll just take on as much or as little work as they want. The flexibility is great to have for the person, they can work when they want. The result? Far more happiness, far better work being done.