I’m not a dev, and I’m not sure if this will be of any help at all, but rivals will usually have final stage early route Pokemon (Dubwool, Staraptor, Stoutland, etc.) so if you’re looking for coverage for the player’s starter, maybe one of the early normal-types can learn it?

That’s good! I know I went more with regional flying types for that role, but region rodent/normal like role can be good for later game move diversity!