@rockydennis , one warior, fully invested in armor, 4 cleric, 1 ranger. ranger after the cleric so the cleric actually use heal instead of attacking, as many cleric as possible to spam heal and thus bless everyone, a warrior with so much armor he take 0 damage.
it is slow, but it can grind as high as you want in a single run. As long as the armor of the fighter is significantly higher than the damage of the ranger (i took ~e3 ratio) then you will always have enough armor for each next level to not die. then clerics will bless everyone to shape slowly until the ranger actually kill the enemy, rinse & repeat