The reason Reds group is to avoid getting stat and being out of the game.
If there is no stat more Reds will go solo and fights will be more even. Also if you can't recall in if you have a count people will be less inclined to go to the bottom of a dungeon to kill the one solo farmer. Whereas with champs the group will come but smart Blues will be able to stage a better defense and have a chance at stopping the attacking group meaning they have to run down again and can't just recall in their next char.
If there is no stat more Reds will go solo and fights will be more even. Also if you can't recall in if you have a count people will be less inclined to go to the bottom of a dungeon to kill the one solo farmer. Whereas with champs the group will come but smart Blues will be able to stage a better defense and have a chance at stopping the attacking group meaning they have to run down again and can't just recall in their next char.