What I want to say is that Aura works best a med, but when there are 2 good aura, team becomes kind of invincible
Let me break it down for you
Lets compare Phoenix and Aura
Other players are usually scattered in the game, while defending or attacking. What Phoenix has to do is that, he needs to go the players low on health and activate healing pulse, which has a cooldown according to how much you charge it, mostly you can only heal 2-3 players at a time, they get healed, and get low on health quickly as dirty bomb is a fast game. but with aura a health station kept at a good place, it helps the team for a long time and give constant health, by the time a health station gets destroyed another is ready. A bad phoenix is of no use, a good one is to some extent, a bad aura usually doesnt revive, but that health station.
Same is the case with other mercs.
What is your opinion?