Then Chespin would be Torterra. Lets forget about defense for a moment and look at attack. With Stab rock he can actually stand up against ice, fire, flying, and bugs. Things that no other grass starter could manage. His only true threat would be steel and fighting. and im sure a nice movepool can help that. GF will not go through Torterra again and i would rather see an offensive grass/rock than a defensive grass/steel imoDo you see cradily having any use? And although grass helps mitigate the added water and ground weaknesses, you are giving chespin a weakness to one of the most used types in most tiers, although it does make a suggestion towards a high defense, hence my doedicurus theory, but I was saying that would have steel/ground as a secondary type.
I hope for a fast physical attacker with grass fighting type, or bulky tank with ground or steel with a secondary type, and even though it is less competitive defensively, I'd prefer ground on a defensive version.