I was just in frontlines and my party had 3 healers (including me). My team alone went to take markets and I immediately noticed that even with just 3 healers in one group could literally make a team unstoppable. As we held markets by ourselves for the duration of the battle with nonstop flames coming at us. Its not an exploit. I would eveb call it a strategy. I mean why would you jeep going after that group of healers? Just ninja cap.