Can I rely on my companions' behavior?

Since the companion configuration in DA:I is not as in-depth as it was in the previous parts of the series I feel very uncomfortable when only controlling my own character.

In the behavior screen I can only enable or disable their "automatic" behavior and set thresholds for mana/stamina, potions, etc.

Will my characters use the best utility skills based on the current situation? I.e. will a mage do an AOE attack when multiple enemies are standing close to each other? Or is the AI not that good? If an enemy has an elemental weakness will a mage use specific spells (if equipped) particularly suiting that weakness?