I have a solution for this. One, reduce the player sprint to a slow run. Sprinting for a limited time then go into a slow run. Two, spawn on avg 3 zombies together. Three, headshots only. Four, zombies should be able to run to a point, about half the speed of the player when he is worn out of sprint. Five, unless the player is a far away, have the zombies follow until A) an new target appears or B) the target has "hidden" from them. This should be easy to get into the game and should make for a more traditional feel of zombie horror. Limiting the sprint and making players get headshots should allow for slower zombies. No need to make them super slow, but the should not instawarp to you. Remember, you may outrun them at first but you have to stop to eat, drink, scavage, deal with jerks while zombies never rest.
