Why would you do this ?
1) Zombie are a pain in the oh yeah !
2) I want to win and that's all !
3) I want fast achievements !
4) Why not ?

Step 1 ) Create a weapon maxed out set then starting number at 5 so each survivor got one for the start. (In my case lazer saber because why not and no need for ammo)
You can take else a LMG sniper rifle (the Ruhm) like in Valkyria Chronicles.

Step 2 ) Full Body armor ( all except head) to do it warhammer style
Step 3 ) Omnitool like the doctor pen (can serve as cooking weapon and so on) if you have read my other guide you know what i'm doing

Step 4 ) Create a character class OP all combat skill maxed out you reduce cleaning (it's for peon)
Associate with your custom character else it wouldn't happen on other survivors.

Optional step ) Create the dream team with OP

Result : 1 man army send in a church 95 zombie dead no injuries.
Some event are a pain so try to diversify weapon is good too