I use them, Clay. When I play Creon, either vs human opponent or vs AI, I always prefer Tortoises over Fire Wagons. I create a Barnstormer or two to have sight of the area and I strike a single target at a time with all my tortoises. Sometimes I also have Automatons in front of my Tortoises in order to prevent Horsemen, Knights, Berzerkers, Spirit Wolves or Blade Demons to reach my Tortoises easily. My Automatons usually die, however they are cheap and serve as cannon fodder pretty well.