The trial is only 15 minutes. It's a fight supposed to be done in ~ 7 min, not on your preferred setup or class and -completely- new. No one knew what the fight was really going to be like until the first people in line started to do it.

Also, based on earlier responses on their earlier challenges like Levi and Ramuh, these fights are generally made just as easy as "story mode" challenges in the game. They're made so a large portion, if not all, of those attempting them at these Live events will win.