The World Federation One Stop Fiqh

Ruling 1522

It is not necessary to perform the qaḍāʾ prayers of a deceased person in the order they became qaḍāʾ except for the prayers that must be performed in a particular order when they are performed within their prescribed time, such as ẓuhr and ʿaṣr prayers, and maghrib and ʿishāʾ prayers, of the same day, as was mentioned previously. However, if someone is hired to act according to the fatwa of the deceased’s marjaʿ66 or according to the marjaʿ of the deceased’s guardian [walī],67 and that marjaʿ considers it necessary to observe the order, then one must observe the order.

66 That is, a jurist who has the necessary qualifications to be followed in matters of Islamic jurisprudence.
67 This scenario could arise when, for example, the walī is the eldest son of the deceased, and it is obligatory for him to perform the qaḍāʾ prayers of his late father, and he hires someone to perform them. See Ruling 1370.