That basically means you devote about half of your AP just summoning stuff which dies in one round dealing little to no damage instead of doing something more useful. Against ranged enemies a Poison spell followed by a Fireball not only deals more damage but also creates a steam cloud or just use a Steam arrow with some ground effects which the AI usually tries to circumvent. Rain + 2 Mages with a cold spells -> easy CC if enemies try to target them.
Or let a melee charge into ranged via Battering Ram, even if they do not fall down they will most of the time attack the warrior. Let your rogue sneak in and let him take out one enemy via backstab, go invisible again and do it again next round. Thanks to Fast Track and some points in speed will enable the rogue to. Make sure to give the melees Bully and provide some CC. Voila, easily trashing any non boss monsters.
In short, the topic itself is a joke. Melees are good to great depending on build, they have the highest single target damage, some nice CC and buffs + best mobility (Battering Ram, Fast Track) especially if you invest some into armor skill for the plate wearing types which you should anyway.
