As someone who has done both Roaring Rapids and GRR in person, I can tell you that the two attractions are not so substantially different in scenery so as to feel like different rides. Dinosaur and Indy don't feel like the same attraction to me, even though they are, because the feel, story, visuals, etc. are sufficiently different. That's not the case with RR & GRR. I went on RR and my overriding thought (other than the pointlessness of building a big animatronic on a rapids ride where the seating configuration all but guarantees that someone will miss it entirely) was "huh, that feels like Grizzly." Then I double-checked by comparing POVs, and sure enough, they're basically the same ride.
Saying a ride isn't a clone because the window dressing is different depends on the situation, and to me, saying that Grizzly and Roaring Rapids aren't clones because of what I feel are relatively superficial theming differences doesn't pass the smell test. They're not different enough to feel like distinct experiences.
