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I'm not very good at judging people, but here's my opinion:
You should take an additional hero, Elaine, and have her absorb the peasants. You don't need peasants on the main hero; instead, take archangels and seraphs because the Necromancer's liches will take down a lot of warriors. Use Archon to resurrect the seraph (if he's badly wounded).
And on the seraph, use Divine Wrath on the liches; more than half of them will die. Also, if you take Light and Purification, Subjugation or Berserk won't matter. And if you use mass buffs, cast Skin, Swiftness, and Blessing, plus something else.
Or: Level up Light, Defense, and Magic Power. Use the Divine Words spell again. Take an additional hero, Elaine, and have her absorb the peasants. Instead, take a stack of armored warriors and a stack of Zealots. Use the armored warriors to remove debuffs, and the Zealots to deal two hits at once or remove misses from spirits.
You can also take two stacks of Paladins and use them to remove debuffs; one Paladin removes Subjugation from the Necromancer, and the other removes it.