For quite some time now, mob stacking has been emplemented in skyblock. But it sucks, and here's why: 1. Ruins farming efficiency. I have a mob grinder, it has a large enough drop to kill anything that spawns. But it doesn't. because of mob stacking it will kill one mob, but a stack of 7 other mobs will survive. 2. Ruins animal farming Say you have two cows, You want to breed them to get more, right? Nope. As soon as you bring them close to breed them, Boom they stack. Egg farms have the same problem, instead of having a pile of 50 chickens above a hopper, you have to have 1 chicken over a hopper and then stack water on top to get more eggs. 3. Makes the game easier. If you are getting swarmed by zombies you could die, but good ol' job stacking makes them all become one zombie to run away from instead of 20, thus increasing the probability of you surviving. Which is bad. But if course mob stacking can be good, as it removes server lag, can increase efficiency in special types of farms, and you can see reason #3 as a good thing. But that's why I think mob stacking is plain dumb and should be removed.