Tanks N and NE
Healers NW and W

Acting Tank DPS S and SW
Acting Healer DPS SE and E

After orbs spawn:

Tanks pop south orb together.
Healers pop east orb together.
Acting Healer DPS pop west orb together.
Acting Tank DPS pop north orb together.

After first orb is popped, each pair rotates cw and pops the next orb.