You actually don't want Whirlwind on them. Every time Life Leech procs, it consumes 5 Mana. So WWing a bunch of mobs, would immediately devour a ton of Mana. Whirlwind is highly unreliable as well, the pet can be completely surrounded by mobs, and never use Whirlwind Attack. They use it more often in single target, than in AoE situations :/
Life Leech procs on outgoing damage, not incoming. The harder the pet hits, the more damage they heal when Life Leech procs. Life Leech only procs on melee hits too, and doesn't proc off of Frenzied Whirlwind ticks (Frenzied Whirlwind isn't affected by modifiers like EoO, Divine Fury, or Con Wep either). The biggest weaknesses of Life Leech healing for pets, is A) mobs that are immune to Life Leech, B) mobs that have extremely high Wrest/Parry skill, and so are difficult to land hits on, and C) taking so much damage that their Stamina drops, slowing down their swing speed and therefore self healing.
Here's how i built my Moldering Ursine.
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Chiv+AI, for maximum single target damage output for his Life Leech to scale with. I gave him 30 Stamina Regen to keep him swinging fast even when taking heavy damage, due to his self healing scaling with his damage output. Moldering Ursines are basically superior to Ossein Rams, not only do they have higher Intensity, but they're even mountable.
The true secret power of Life Leech pets, is the fact that their Life Leech can still heal at full effectiveness through Combat Training: Berserk. Upon reaching half health, Berserk causes the pet to gain a ton of damage output, and damage resistance, but at the cost of severely reducing all incoming heals (other than Life Leech for pets). It's basically a "Kamikaze" mode for any other pet, they'll eventually die, but dish out a ****ton of damage during it. Life Leech pets can survive while Berserk, and dish out a ton of damage. For example, here's a screen of my 120 Chiv+AI Ossein Ram dealing a 436 damage AI during EoO while Berserk (that same hit, took the Ram from half health to full). I've heard of others saying they've seen 500+. That Ossein Ram was at GM Tactics, and didn't have the TP for anything higher. Moldering Ursines do have enough TP for full 120s, and so can hit even harder when Berserk, and have higher HP.
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