Suzumiya Haruhi.
One snap of the fingers. The zombies are gone. Of course, that's presuming her awareness of her powers.
OK OK. If the zombies piss her off - and likely they will -- she'll inadvertently wipe 'em out. Even then, she'll make the zombie encounters fun, by being initially very enthusiastic about the whole zombie thing.
Who am I kidding? With Haruhi - I'm a dead man.
So y'know what?
Nagato Yuki.
Count on her to hold off the zombies... until Haruhi does wipe 'em out.
The whole SSS crew (Angel Beats) - incl. Kanade
They already fought some zombie-like things -- in whatever afterlife they're in.
Rias Gremory (High School DXD)
Chances are -- she'd be in command of the zombies. Maybe, with these devil powers of hers. I could be wrong here.
The Strike Witches
Magic. Girls flying. So guess what? Up in the air - the zombies can get them and can easily pick off the zombies.
Need an airbase? Well, I haven't watched Girls n Panzer yet to see if they're reliable on the ground. Otherwise, have everyone else listed guarding the base.