These Coliseum ranking complaints are more than valid, especially as it'll only get worse as the player count dwindles. My opinion is that Edge should make it so that inactive critters are available to fight - more options on who to fight, now unused builds will be present again and it'll fix the Edge site top 10 critter rankings.
People seem to be pointing out that luck is the major factor in this game. It seems that all the times I've had enough money to buy Divine Edge and been in the right condition to fight the dragon, Divine Edges are nowhere to be seen.