Any t5 mob shard is more or less the same animals give less xp, its kind of how fast you can auto kill the mobs with turtles or iron golums, also the number of blocks above ground is a factor as when mob is outside a set range of shard spawner the shard spawns new set of mobs, but keep in mind thats if you have too far a drop mobs could die before they get to the turtle/golums, I normally make multi grinder with a number of shards 9-12 blocks over water to bring them to 2 turtles (yes only 2 as less server strain) atm I am messing about with quicksand + snow/ice blocks as my enderman grinder no xp but easy to keep them contained & collect, endermen will not pick up snow/ice.