You are exactly correct. Both of Pepin's books are heavily-illustrated and provide step-by-step instructions on cooking almost anything. "Larousse" is the theory, Pepin is the practice.
Larousse Gastronomique is excellent, but I would not expect what it says about sautéing or poaching to enable anyone to do those things successfully who was not previously able to. I don't have Pépin's books but my guess is that they would be much more helpful to someone in that situation.
You are exactly correct. Both of Pepin's books are heavily-illustrated and provide step-by-step instructions on cooking almost anything. "Larousse" is the theory, Pepin is the practice.