There's relatively less zombie combat in this compared to the first and there should be even less. The worst part is those sections where you start out undetected and can't just run past them.

Unlike with human enemies, these zombies seem to always know where you are so you can't play hide and seek. Can't take cover or hide in vegetation cause they'll run at you. So you're forced to hit restart checkpoint whenever you get detected cause there's so little ammo (noob difficulties don't count)