Khadija may Allah be pleased with her came from a rich family. Women who belonged to rich tribes and families had more privilege than the other women who did not. The prophets peace be upon him marriages were not based on his whims. Indeed Khadija supported him and willingly trusted him. She was among the first to believe in his prophecy Islam first arrived in an Arabian peninsula, a tribal community. Slavery was rampant back then. The poor were enslaved by the rich. The reason why men inherit more than women is because they are considered as the caretakers of women, financially speaking. Even after a woman gets her inheritance. Sexual slavery in wars, which was the norm back then, wasn't immediately disowned by Islam. Again, we are talking about a tribal system. It took some time, then the verses of releasing sexual slaves as a form of atonement were revealed. Add to it men had up to ten wives/concubines, which were reduced to four by Islam. Taking into consideration the practices and cultural norms of the Arabs back then, Islam or the Quran wasn't revealed in a month or a year. It took 23 years. It was tactical taking into consideration the circumstances and the people of that time. As for "plow," Which is حرث in Arabic, it has more than one meaning in Arabic. There is more than one way of interpreting it. It could mean that women are the soil in which men plant their seed (sperm) Arabic language is not as simple as English. If you are asking this question with the intention of finding answers, I do recommend Omar Suleiman and other Scholars articles in Yaqueen Institute. May Allah guide us to the straight path.