I'm still not fully certain what GameFreak was thinking from this dynamic. Tinkatons are supposed to be Corviknights natural predators, hell, their hammers are supposed to be made from the scraps of Corviknight armour, yet Tinkaton doesn't naturally learn any move that is super effective against Corviknight.
In fact, they don't get any rock type moves at all through leveling, they have to learn Rock Slide and Stone Edge through TMs. Y'know, the two moves that are the most likely alluded to in their Pokedex entries
On top of that Corviknights are super bulky. They have a base 105 defense stat. Compared to Tinkaton's depressingly mediocre base 75 attack, those rocks would barely be making dents after losing out on STAB. That's even ignoring the fact Rock goes neutral to Steel/Flying or that Corviknight naturally learns Iron Defense. Tinkaton's signature move is steel type, their second highest damaging move is fairy type. Both of which Corviknight resists.
I want to love this dynamic. I love the idea of this dynamic. I do not think GameFreak thought any of this through, however, which bothers me and my dumb stupid OCD nerd brain to no end.