Farming using AOE - Mob AI question

As previously stated, there are 2 kinds of scatter.

The first is AoE scatter.
This kicks in when monsters have lost some of their health due to damage from AoE skills, and applies to both mellee and ranged creatures. The way this works behind the scenes can often be confusing as it produces what can be intepreted as random scattering. In a nutshell, a group of creatures will scatter after being hit by damage from the same AoE source repeatedly over a short period of time. Now, while both Fireball and Firestorm are AoE, the difference between them is that Fireball is a one-shot thing while Firestorm pulses, delivering damage each time. Behind the scene, the game makes no differentiation betwen the two in terms of how cretures scatter, however, in practice the difference lies in how fast the damage can be reapplied. Take for example a skill like Zealot's Fire, which does AoE damage whenever you use a skill on yourself. Casting a spell once while under it's effect will not cause scattering. However, casting many spells in quick succession will cause monsters to scatter. If Fireball had no recharge, and you kept spamming it, you will see monsters starting to run from it. There is no hard and fast number for how often such AoE needs to trigger before scattering starts but from what I remember, Meteor Shower, which hits every 3 seconds will never cause AoE scatter on it's own, but spells that pulse every second such as Firestorm will always cause scatter.

The second is Mellee scatter.
This type of scattering occurs when you have more than 3 mellee creatures aggroed on you at teh same time. What happens is that the creatures will "take turns" fighting you, retreating a little whenever their health drops below a certain point. Whenever the number of creatures changes, or one of them has regened enough to feel brave enough to come in, they will resettle.
Melle scatter is very different to AoE scatter. It does not matter where the damage comes from or how fast it comes, the only factors that come into play are the number of creatures and their current health. Also, this only applies to melle creatures, which can include some casters. The more creatures you aggro, the more sensitive they are about running away, when they get low on health. Also, the health margin for retreat seems to be influenced by the number of creatures agrroed. Certain mellee casters, while being subject to scattering will get no benefit from it because while they retreat, why will continue to spam their spells, thus still being considered "in combat" and never starting to regen, however this varies from mob to mob.

You can avoid scatter of melee mobs by getting them stuck in a narrow corner or something like that. If you know a zone well you might find some good spots.