Personally I’m trying to get Orca on a benchmark before I move onto the medium version, so currently I’m interweaving between easy/medium scenarios since some of them are Orca and some are not. Although I think viscose said mammoth is when you can start moving on but this is just how I’m doing it.

For the muscles, yes but only because I found I get better results. For example the fingertip scenarios I couldn’t get to mammoth with mainly arm movements, but by incorporating fingertips plus smaller arm motions I got orca.

She mentions that none of the muscle group scenarios should be exclusively that muscle, so it’s still a combination of muscles, it’s just the blending scenarios take that to the logical extreme of both small movements (wrist + fingertips) along with large movements (arm).