Some imagination had to go into this entire section of the story. The ancient legends which have survived to our time about these events are very sparse and provide few details. They basically say that Cronus ate his own children and that Zeus escapes this fate because his wife, Rhea, tricked him by giving him a rock instead. A rock? And he didn’t notice?
So, I’ve embellished a little. Some help from mom Gaia, some magic so Cronus sees what they want him to see. Now we have the mighty king of the gods eating a rock and believing it’s his son.
The entire Age of the Titans was pretty much like this. It was not a time the Greeks put much thought or writing into. It was all part of their origin story as to how the Olympian Gods, the ones they really cared about came to be, so they didn’t write a lot. Add to that the small amount of what they wrote and believed that has actually survived the 2500 years since these stories were written down and you see the problem.
In the year 5000, it will be interesting to see what people know or remember about Star Wars or the Avengers.