>>44625009No, see the best way to differentiate AND balance steel and rock is by making rock the "ceramic" insulating type, and steel the ..well..metallic conductive type.
>RockWeak to: Grass, Water, Steel, Fighting
Resist: Normal, Flying, Poison, but also Electr/Fire/Ice as it is insulating, and even Ground (I agree, on that, Ground attacks are either Rock-like or Sand/mud related)
>SteelWeak to: Fire/Electr/Ice
Resists: Dragon, Fairy, Dark, Normal, Psychic, Rock, Grass, Bug, Poison immunity
So with the exception of Fairy and Psychic, Steel is open to most special types. I would even make Steel weak to Sound if possible.