The best part of ATZ, or any Two Hour Wargame, is that Its your game. If you want 30 zeds to show up at a spawn, put them down. If you want the crowd to muffle the gunshots (I like that idea alot, btw) then say thats whats happening. Ed always encourages the players to add or subtract to the rules for thier own liking. You make a really memeorable cinematic RPG wargame that way. Good luck, have fun!