If they are in a far dessert why can't Rainbow and Flutters use their wings to fly? And for Twilight she can fly and use magic but why didn't she just fly and carry Spike, AJ, Pinkie and Rarity? (If Rarity did not master flight spell by Starlight) with her telekinesis magic? That should have just speed things up ahead instead of walking...

Your welcomeBut what I am try to say is like they have done this or done that like this for example that bothers me in my head...