What is the evidence for the Maliki school's view that the Imam stands at the shoulder of the woman and the waist of the man in the funeral prayer, and is it considered authoritative?

The well-known opinion in the Maliki school is that the Imam stands at the middle of the man and at the shoulders of the woman in the funeral prayer. They justify the Imam standing at the woman's shoulders by saying that it screens her from people, and it is feared that if the Imam were to stand at her middle, he might recall something that would invalidate the prayer. There is another opinion among the Malikis that agrees with the view of the majority of scholars, which is that the Imam stands at the middle of the woman. Al-Qabisi holds that what is narrated in Al-Mudawwana from Ibn Mas'ud regarding this matter has a problematic chain of transmission and includes an unknown narrator, and it contradicts the authentic hadith. Therefore, the Imam standing at the head of the man and the middle of the woman is more deserving of adherence because it is what the authentic hadith indicates, and it is the view of the majority of scholars.