Thanks for playing and the feedback!
There is a hint that several words serve more than one function ("Which words are roles, actions and targets? - Yes."). You can also set your healers to heal the lowest health player via HEAL - HEAL - THERE.
As you said, combat is very simple in the prototype because I did not have enough time to implement more complex mechanics (or partially had to disable them due to last minute bugs). Both healers and tanks are also too strong right now. Tanks generate too much aggro and healers cannot run out of mana.
Some ideas to make fights more engaging is adding in boss AOE dmg, targeting players outside of aggro table order, full aggro table resets and environmental effects. Basically mechanics many MMO bosses also have. E.g. if a boss channels a large AOE spell tanks and melees dps should move out of range (TANK/MELEE - GO - RANGE) while ranged dps should stop attacking to not get aggro.
There are some more fights you can access from the guild screen, e.g. the axe gang with lots of adds (target them via e.g. RANGE - RANGE - MELEE or TANK - GO - MELEE).