The thought is that Humans have already used (abused?) machinery such as bulldozers and chainsaws to drastically reduce the water holding capacity of the landscape, and our task is to use these machines in one big push to drastically improve the water holding capacity of the land permanently and then to not need to use them any longer.
See any of Zepp's large scale projects. He has been successful, and failed a few times, in projects all over the world with some amazing transformations.
If you’re building large low-input beds that could last for a decade or more, a tractor might be an appropriate tool given your local constraints vs. a crew of horses/humans and a great deal of time/energy.
Use any means nessasary to move the current system into one that will self-renew and self replicate.
That's permaculture. Set into motion a permanent self-renewing system!