Salam,
There is a priority inversion between legs/waṣyya and inheritance/warth : Contrary to popular belief, the Qur'an has not indicated a single modality concerning the notion of transmission of post-mortem property, but two: The testamentary legacy/al-waṣyya and inheritance/al-warth.
And, of these two Quranic measures, the testamentary legacy or waṣyya is the main one and inheritance or warth is secondary, whereas Islam has reversed this order of priority.
- The testamentary legacy/al–waṣyya => [2:180]
- Priority = > [4:11-14] :
(1) debt
(2) testamentary legacy / al-waṣyya
(3) Inheritance in shares of the remainder / al-warth
Thus the Qur'an conceives testamentary legacy/al-waṣyya as the general measure and inheritance by shares/al-warth as only a secondary measure concerning the residue not bequeathed by will, i.e. a special residual case. However, Islam, on the other hand, has generalized the practice of quota/al-warth inheritance by giving it priority over testamentary legacy/al-waṣyya which it has particularized and reduced to a minimum.
al-warth => One should not generalize about particular cases - at best draw inspiration from them.