Zombie stage strategy

This is about fending off zombies.

As critical attack would do extra damage on human enemies, critical attack or headshots is very lethal on zombies. It kills a zombie INSTANTLY REGARDLESS THE DIFFICULTIES.

So heres the strategy to fight zombies:
1. Use leader which gives crit bonus. Good ones are molly (+30 crit) siddiq (+16 crit). Ally faction sipporter leadership skills also relevant to add the chance.
2. Use crit bonus weapons. Rare weapons usually gives +20 crit.
3. Use character with AR buffs to add crit. My favorite is three star sophia with her hope bringer AR (30 att and 30 crit) for two turns.
4. Use regular attacks on zombies. ONLY regular attack has chance to be critical attack, while AR attack is not.
5. Items to use against zombies: bloody shirts, guts, blue vials (weak zombies) or flashbang (strong zombies), oxide for meelee or sharpshooter for ranged.

With the above strategy, I have completed zombie stages in ultra rare gear event which recommend S1++ team. Done it with an A+ team.