Bishops appoint others and delegate as they take advantage of expertise:
[25.] Commissions as well as councils or committees established by the Bishop to
handle “the promotion of the Liturgy, sacred music and art in his diocese” should act in accordance with the intentions and the norms of the Bishop; they must rely on his authority and his approval so that they may carry out their office in a suitable manner[Vicesimus Quintus Annus 21; Sacrosanctum Concilium, nn. 45-46; Pope Pius XII, Encyclical Letter Mediator Dei] and so that the effective governance of the Bishop in his diocese will be preserved. As regards all these sorts of bodies and other entities and all undertakings in liturgical matters, there has long been the need for the Bishops to consider whether their working has been fruitful thus far,[Vicesimus Quintus Annus 20] and to consider carefully which changes or improvements should be made in their composition and activity[Vicesimus Quintus Annus 20] so that they might find new vigour. It should be borne in mind that the experts are to be chosen from among those whose soundness in the Catholic faith and knowledge of theological and cultural matters are evident.
Experts with evident ability: this is a good standard, though not always evenly applied. Another good piece above is the “long” need for bishops to assess their work and be assessed. Good leaders also know to include people who won’t just be “yes people,” but those who can exchange respect, as well as bad news, when it must be delivered.