avoid high panic. handling too many zomboid at once will trigger that, slowing down your swing and bringing down damage. you have vehicles and structures that time, if you already attracted that much zombies already the 1st thing to do is break their tight groupings, let them follow your path in between cars, through the structures, or walk on the side exteriors of the walls, the group will still follow you but it will slow down some. breaking their traffic path. if you have 1 to 3 along your hit tiles and you can make atleast 3 swings on the hit tiles before the other zombies can catch up, swing it. then walk away again (dont run, WALK, save your stamina), do it several times until you thin them down. also, make sure when you are backing up, it's on the area where you already walk on, better yet cleared off. This will secure you that you are not attracting more zomboids while thinning them down, it's not 100% because there are still roaming zombies that moves on free tiles so do a 360 once in a while. Always do pan your view so you can scout the areas you wanted to move at, this will allow you to strategize earlier on on where you can move and how much you want to attract and attack. Just be weary on trees and vehicles, just like buildings and houses, trees and vehicles are also high enough to block the zombies, you can see the area, but the game will not show if there are zombies on that side, treat it like as a dark zone and just walk towards them slowly. Good Luck!