because mike clarke has more experience, comp results and has some sick doubles that weren't in his edit, i'm pretty sure jon knows that clarke has a double 14 along with his dialed 9's and cork 5's, all of which are perfect for the competition - Gus is sick but Jon probably wanted someone that knew how big comps and photoshoots worked for his first JOSS ever so that there isn't some 16 year old that for what i know hasn't been to a major comp getting lost or confused in all the media coverage
but i think he could possibly take Jossi's spot because he is a dope skier