In *World out of Time*, Larry Niven explains it well.

[![book cover][1]][1]

He had a motor in the atmosphere of one of the ice giants (I forget which) that shot the planet's atmosphere out to cause reaction. That planet was guided to pass the planet to be moved, nudging Earth with its slingshot effect.  This pretty much destroyed the ice giant, but *carefully* moved Earth, intact.


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Note that the planets *did* move around, substantially,  even switching order, ejecting some, dropping others into the sun, smashing some together.

So why can't "nature" end up putting them where you wanted all along?

My novel answer is **chaos**.  Nudge small rocks using a small amount of energy. That influences larger rocks to nudge their orbits. The larger rocks influence still larger rocks, etc.

You cause a dynamic instability, and through continued application of small changes, make it settle down the way you intended.

  [1]: https://i.sstatic.net/hNNOJ.jpg