It is narrated from Imam al-Sha'bi (may Allah have mercy on him) that Sayyiduna Zayd (may Allah be pleased with him) did not make them share; he gave the third to the maternal half-brothers alone, to the exclusion of the full brothers. Hushaym said: I objected to him and said: Sayyiduna Zayd (may Allah be pleased with him) used to make them share. He said: But al-Sha'bi narrated it to us like this from Zayd, that he used to hold the same view as Ali (may Allah be pleased with him). I objected to him again, and he said: Ibn Abi Layla is (the judge) between me and you.
The authentic narration on this from Zayd bin Thabit is what has preceded; this narration is reported by Muhammad bin Salim alone, and he is not strong.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12481