Is it permissible for a poor father to take from the pension of his minor orphaned son, which he receives from his deceased brother, in order to spend it equally on himself and his remaining siblings?

A father has guardianship over his minor son's wealth and may spend from it on him in a reasonable manner. If the father is in need of money, he may take from his son's wealth that which exceeds the son's needs, because the maintenance of a poor parent is obligatory upon his wealthy child, and reaching puberty is not a condition for the obligation of maintenance. However, a father spending from his son's wealth on his needy siblings is not permissible according to the majority of scholars, while some scholars hold the view that a brother's maintenance is obligatory upon his poor brother.