You’ve mixed documented events with your own interpretation of their motives. Yes, classical Islamic sources report Aisha’s marriage contract at six and consummation at nine. But “he married her because she was his best friend’s daughter”, “he offered marriage to free her tribe”, “he married Zaynab to satisfy himself”, and “Sauda lived a miserable life” are not established facts. They are interpretations. For Juwayriyah, the transmitted account actually says she sought help securing her freedom, accepted Muhammad’s marriage proposal, and her people subsequently freed many captives because of the marriage. And with Zaynab, the Quran itself presents the marriage in the context of ending the pre-Islamic treatment of adopted sons as biological sons, while explicitly rebuking Muhammad for fearing people's reaction. You can criticise these events. But if you're going to argue against Muhammad, argue against what the sources actually say, not motives you have inserted into them.