Is “Cause of mending the sky” true?

The Huainanzi, chapter 'Lanming Xun', records that 'the four poles were broken, the nine provinces split', so Nüwa smelted five-colored stones to repair the azure sky. The Huainanzi, chapter 'Tianwen Xun', records that Gonggong angrily struck Mount Buzhou, causing 'the pillar of heaven to break, and the cords of the earth to snap'. The direct causal link between Nüwa mending the sky and Gonggong striking the mountain does not exist in early texts such as the Classic of Mountains and Seas; it is a mythological system gradually pieced together by later generations.