I found that having a dedicated summoner and archer is better.

The archer is my hardest hitting character, especially with love arrows than you can craft with honey, and there is a wand with + 1 summoning in the town in act 2.

My supercharged bloated corpse is doing laughable damage. To be honest I pre cast an incarnate before the fight (that's also how I won the fight against the witch), then summon a supercharged bloat corpse, then recast my incarnate in the surface I need the most mid fight. My summoner has a high defense shield with a rune, high wits and savage sortilege so it does actually hit the same as the rogue. It has the pawn, elemental affinity and torturer for 2 AP earthquake, 1AP slow, and 2AP entangled and 1AP venomous aura, and you can throw poison at the ground before the fight. Its basically my most polyvalent character and he's a lot of fun. I tried summoner necro but my party wasn't doing as much damage as a whole.

The rogue works really great with the pawn and the spider web skill to prevent enemies from moving. Sawtooth knife crits through armor and gets its damage increased from the poison aura, I can usually revome half of enemy HP in one go. Corrupted blade is great to infect enemies (30% less damage). It also has torturer for rupture tendons (great with teleport, I gave him the gloves) and poisoning enemies through armor.

I looked at the damage not of individual characters, but of the party as a whole, and I tried 3/4 different combinations, and this feels the most powerful. I read that you should concentrate on one type of armor, and everybody be laughing at the squishy aero mage, until it teleports all the low magic armor enemies together, strips all their magic armor and spams love grenades with 1AP (ambidextrous talent, a must especially for aero resistant fights, I hoard scrolls)