Is it permissible to appoint an executor for only a specific part of the will?

Primary text

It is permissible to appoint a man to execute only a specific portion of the will, such as appointing someone solely for distributing a specific part of the bequest, paying debts, or managing the affairs of the children. The appointed person is restricted only to what has been assigned to him. This view is held by Al-Shafi'i. The reasoning is that the authority gained is through permission from a human agent (the testator), thus it is limited to what was permitted, analogous to an agent (wakil). Furthermore, the principle of divisibility applies to permission, unlike the authority derived from kinship, which is indivisible.