My NWN2 "main" is a level 10 wizard. He was a bit squishy for the first couple of levels but soon gathered a collection of powerful area of effect spells. At normal difficulty setting the game became too easy because damage does not break crowd control. My wizard could wade into a bunch of mobs, stun them all and fry them all with few aoe spells.
I upped the difficulty to hardcore rules. This allows mobs to hit a bit harder but the most significant change is that area of effect spells now damage friend as well as foe. This friendly fire aoe certainly adds a new element of strategy to the game. Position and timing become critically important if you want to avoid incinerating yourself and your team.
Fallen comrades are resurrected after each battle so you could play a sacrificial strategy stunning and killing friends and foes alike. That strategy doesn't sit well with a "good" character alignment though and it is risky. Mobs often break loose from crowd control and the wizard needs to be protected.
I prefer to play slowly and cautiously. My wizard, druid and rogue hide in the shadows while a heavily buffed fighter pulls a large train of mobs into a carefully prepared crowd control trap. Once trapped the mobs are easy pickings for the rogue (sneak attack against stunned targets) and carefully placed spells. The fighter and druid pick up stragglers, keeping them away from my wizard.