How are estate distributions handled when three claimants die sequentially before the lineage of the claimed child is established?

Primary text

If there are three claimants, and one dies leaving a son and 1000 units, the second dies leaving a son and 2000 units, and the third dies leaving a son and 20,000 units, and then the child dies leaving 15,500 units, and he was acknowledged by *Qafah* to be free-born, his mother receives one-sixth, and the remainder is divided equally among his three brothers. If their deaths occurred before the child's lineage was established, the mother is given one-third of his estate, which is 1500 units, because the minimum scenario is that he is the son of the claimant with 1000 units, inheriting 500 from him. The amounts placed in escrow from the estate of each claimant are returned to the sons of the first and second claimants, as this belongs to them from their parents, whether or not he was their brother; if he was their brother, he deserves that amount and more through his inheritance from them. 9,333.33 units are returned to the son of the third claimant, and 666.67 units remain escrowed between him and the mother, as it is possible he was his brother, meaning he died leaving 14,000 units, one-third of which goes to his mother. The remaining 2500 units from the child's estate are escrowed, claimed entirely by the son of the first claimant, and 2,333.33 units are claimed from it by the son of the second claimant, meaning that amount is escrowed between them and the mother, and one-sixth of the 1000 units is escrowed between the mother and the son of the first claimant.