Too often we don't think about it, ask if they can do it or put it in a job description. We have a need, create a position, fill it and never address the most important question.
Can this individual multiply themselves by raising up others to do what they do? It is the "develop, empower and release" commitment and ability of your staff. If they cannot do it, or don't do it or won't do it and are in ministry positions, your ministry is not scaled for growth and one either plateaus or must hire additional staff as one grows.
And it violates a basic Scriptural principle that those in full time ministry are primarily there to raise up others for ministry - Ephesians 4:12.
The development of people is one of the highest responsibilities of every individual in full time ministry but it usually does not even show up on a job description. Nor, on annual reviews (where they are done).
What would happen if 20% of your staff's time were spent in developing others? You would, over time, gain new staff, whether volunteer, or part time because you made the investment.
Why do we wonder why we don't have enough volunteers for our ministries? Often it is because we didn't make the investment in them. We did not develop (mentor and train), empower (give real responsibility) and release (let them fly on their own).
When we make real investments in people, serious investments, the return is huge. It is what Jesus did with His disciples and what Paul did with the likes of Timothy and Titus. They multiplied themselves in real ways.