That's an interesting load of Taqiyya. It says "The discussion of orphans and their care continues well into Surah An-Nisa further emphasising that marriage to more than one woman is only permitted in the unique case stated very explicitly within the verse itself".
Yet, looking at the list of Muhammad's wives and concubines, Mo married six year old Aisha, after having earlier married Sawda bint Zam'a. Aisha was not a widow, nor an orphan.
Mo's next wife, Hafsa bint Umar, was also not a widow, but the daughter of his wealthy friend Umar.
Then we have Rayhana bint Zayd ibn Amr :
Her first husband was one of the 600-900 Qurayza men whom Muhammad beheaded in April 627. He enslaved all the women and selected Rayhana for himself because she was the most beautiful. When she refused to marry him, he kept her as a concubine instead. She died shortly before Muhammad in 632.The only prerequisite, in Islam, for taking a second, third, or fourth wife, is the the husband be able to "deal justly" with them, i.e., be affluent enough to provide a suitable standard of living for each, and provide each with sexual relations. Reference: The Concept of Polygamy and the Prophets Marriages