when every AoE kills your own team members...

Started with 2 mages one pyro one earth, cleric, and tank.

Healer seems absolutely worthless ends up healing her self the whole time. Tanks sits in AoE's from mages or stands as far away as possible to be pretty useless.

Is the game designed to just run straight mage, straight ranged phys, or straight phys melee builds no AoE?

I am in Act one started two different profiles just trying to figure out what classes I like. Really find aoe from pyro neat but frustrating because of self damage to everyone in party.