You had a paladin, a berserker, and a warrior vs two warriors, and a special guard. The damage output was in your favor, but the justices won. I kept seeing overhead crushes.
Back before combat changes, all things were decided by either 1) dirt, 2) bash, or 3) trip. I don't that's changed yet -- I would add hobble to that list. Lags and disables keep your enemy from doing anything.
From a knight point of view:
Dwarf Berserker -- use hobble, use rage, and have the paladin cure for all his worth. More attacks, more damage outputted. If Paladin's keeping you well, the Justices will flee before you guys flee. They won't retarget the berserker until paladin's dead. Higher hitpoints + higher damroll is good if he's not disabling.
Half-elf Warrior -- dirt and rescue. Best tank out of the three with three defenses, blind fighting, etc.. etc. They won't target you because of that, when you rescue, you'll have attacks of opportunity. If anyone should be eating damage, it's you. When you get low, start calling for a retreat.
Paladin -- this is what I always found lacking when I played Messian, a cleric. Someone that'll keep the group healed and better off than the other party. That should be the only purpose of the paladin, to keep other people healed, sanc'd, whatever. Maybe lead and crusader as well.
I noticed you were using purple potions -- why? Get defender's or sanctuary for fights like these. You don't want aura to drop in the middle of combat and eat 6 attacks of CAPS.