At www.skyandtelescope.com/astronomy-new/when-and-how-did-the-moon-form/ (sent in by Jovan Kesic) … references various studies such as a Nature Geoscience article'When and How Did the Moon Form?'. It seems that no one idea ticks all the boxes according to Kelly Beatty of Sky and Telescope. We have one huge collision and an opposite theory of multiple small impacts – but worlds in collision is the theme of both. Another theory published by Science Advances has the moon fully formed shortly after the beginning of the solar system – and one may wonder why not at the very beginning. Another theory suggests the moon had a lot of water when it first formed.
At https://phys.org/print407403660.html … earth began with a solid shell. There were no plates – they came later. The solid shell cracked and buckled, giving rise to the plates, we are told (Nature, Feb 27th 2017). In reality, another piece of guesswork, like the formation of the moon. Good to get ideas out there for other people to peruse and evaluate.