How will Allah combine spouses in Paradise for only one husband? And will the wives of Prophet Muhammad, peace and blessings be upon him, and his descendants be at the same level, as in the verse: "And those who believed and whose descendants followed them in faith – We will join them with their descendants"? And will all other spouses be with their wives and children?

What appears is that the Wasilah (a high station in Paradise) is specific to the Prophet (peace be upon him) alone. However, Allah will join his wives, the Mothers of the Believers, with him as an honor to him and a completion of his blessings, so they will be with him in his rank as followers. As for other people, a man will be with his wives and children if they are among the people of faith.