Well, I think it's a bit different. The Little Mermaid takes place in an unidentified kingdom on the surface (it seems vaguely Italian or Mediterranean, I guess?) and an underwater Atlantian kingdom, so race doesn't matter. The original Dr. Strange comics have all sorts of uncomfortable racial and religious tropes; it's about a white guy who finds magical order Tibetan monks, not only learns their magic, but becomes even better than them at it, and moves to New York with an Asian man-servant named Wong who serves him tea. Changing up the races and backstory on that one isn't just acceptable, it's advisable.