The desert guy might not actually be a good teacher, at least for her personally. There's all this stuff he might be able to do because of his physique and innate aptitude that wouldn't work for her.
More extreme version: Imagine learning martial arts from The Flash. "OK, first, your opponent will attack you. Now, it's coming in slow motion, so don't be hasty when you lazily sidestep--remember, about the only way you can get tagged is if you accidentally step straight into the blow. Now, strike with blazing speed that makes it impossible for them to even think of blocking . . . you can't? I'm not sure you're really cut out for fighting!"