@DirtySnipe - find the errors in the RPT log, and fix them. Nothing I can do with what you described.
@Opticz - what torturedchunk said first of all, and then check what commanderretra said after. Then check your RPT and every file, figure out all the errors you got!
@torturedchunk@commanderretra -

thanks.
@SURT78 - you've messed up somewhere, and change the forcespeed settings in the zombie_agent.fsm AI. I don't know if you're using the addon, but make sure you are current with everything. Headshot only is in fn_damagehandlerZ.sqf - called from compiles.sqf, you can just remove the call.
And no, it is not possible, as regular dayz's zombies are too CPU hungry to have more of them.
@ALL: Targeting update coming soon, for everyone who's having issues where you can't properly hold zed's attention. Also tweaking here and there, keep your eyes on the github, update in a couple days at the most.