I should perhaps clarify that I’m not concerned with my own case. I have no intentions of playing a Planetouched in the near future. I’m concerned from the point of view of design, and how mechanics should reinforce story. An Earth Genasi Aasimar should have traits that suggest both angelic radiance as well as petrous gravity, and if they’re both simply Planetouched variants, that’s harder to express mechanically.You could. You just would not get the powers. You can still be creative, though. Nothing stops you from coming up with a great back story for how you are a mixed Genasi.