How sound is the Hadith narrated by Abu Hurairah from the Prophet, peace and blessings be upon him, in which the Sufyani and the swallowing up of the army are mentioned?

The hadith of the Sufyani is weak and not authentic. The defect in the hadith is the tadlis (deceptive narration) of Al-Walid ibn Muslim, specifically tadlis al-taswiya, which involves dropping the shaykh of one's shaykh. Muslim did not narrate from him. Another defect in the hadith is the tadlis of Yahya ibn Abi Kathir from his shaykhs. As for the sinking of Al-Bayda, a sound hadith has been narrated in Muslim and other collections from Hafsa (may Allah be pleased with her) with a different wording. The hadith of the Sufyani has been deemed weak by Shaykh Al-Albani, Dr. Al-Tarifi, Dr. Hatim Al-Awni, Shaykh Hammoud Al-Tuwaijri, and Shaykh Ibn Uthaymeen.