Is the poor prophet superior to the rich, sovereign prophet, such that Muhammad (peace be upon him) is superior to Solomon, and does this mean that the poor scholar is superior to the rich, sovereign scholar?

The Prophet (peace and blessings of Allah be upon him) chose to be a servant-messenger, preferring this over being a king-prophet. This is because a king-prophet may dispose of some permissible things by giving to whomever he wishes and withholding from whomever he wishes, whereas a servant-messenger neither gives nor withholds except by the permission of Allah Almighty. It is inferred from this that a servant-messenger is superior to a king-prophet, and that prophets like Ibrahim, Musa, Isa, and Muhammad are superior to Yusuf, Dawud, and Sulayman. Furthermore, whoever does what Allah loves and utilizes permissible things to fulfill what Allah has commanded him, he is among the Muqarrabun (those closest to Allah). As for one who performs his obligations and engages in permissible acts that he loves, he is among the Abrar (the righteous). Regarding the issue of the grateful rich person and the patient poor person, Shaykh al-Islam favored that the better of them is the one who is more pious.