That might be true if people are trying to do 4x teams for Guild Wars, but like @Powerplay, I think the best way to deal with that team is to kill Justice first and fast. That kneecaps the team and everything else is mopping up. Personally, and I've been saying this for months, Amira is the best troop to do that. The fact that she is also mana-shielded and does double true-damage to Blue makes her a serious problem for Mab, as well.
I don't need to rely on a coin-flip team because it isn't worth the gamble: I can methodically annihilate that team 19 times out of 20, and on the 20th time, there won't have been anything I could have done, no matter what team I brought. If I needed to gamble for every last GW bonus, I might sing a different tune.