first activator: spawns the mobs if the wool below is green
second activator: counts how many mobs and changes the wool beneath depending on the amount of mobs in radius
third and fourth: creates/removes the scoreboard objective that's responsible in the entire thing
second activator: counts how many mobs and changes the wool beneath depending on the amount of mobs in radius
third and fourth: creates/removes the scoreboard objective that's responsible in the entire thing