What is the distribution among heirs when three full-blood brothers drown simultaneously, leaving a mother and paternal relatives (Asabah)?

Primary text

If the death order is presumed such that one brother died first, his mother receives one-sixth, and the remaining five-sixths are divided between his two brothers. Each of these portions is then distributed among the mother, the paternal relatives, and the surviving brothers based on the stipulated primary distribution factors (e.g., twelve parts initially). The mother's total share increases by receiving portions from the estates of the two brothers who survived the first deceased, and the remainder goes to the paternal relatives.