
Originally Posted by
Claymore65
Important Math misconception! You don't actually get "95%" reduced damage from combining cooldowns like that. The damage mitigation isn't completely additive, otherwise it would probably be possible to get above 100% mitigation, which means you should hypothetically heal damage from being attacked.
Using some very rough math, let's say an attack deals 100 points of damage to you. You have two cooldowns, both of which reduces damage by 50%. Hypothetically, that should grant you 100% damage reduction, meaning you take no damage, right? (50% + 50% = 100%, or 100 - 50 - 50 = 0)
However, that's not actually how it works. Each one is applied to the total damage sequentially. So, in this simple example, the first cooldown reduces the total damage by 50 Points (100 - (.5 * 100) => 100 - 50 = 50). The second cooldown then activates. This reduces the total damage by 25 points (50 - (.5 * 50) => 50 - 25 = 25). In the end, you will take 25 damage, even though you were "supposed" to take 0 damage. The total mitigation of the two abilities combined is 75%, not 100%.
That's not to say stacking cooldowns is ineffective in the slightest, but it's not as simple as you're making it out to be. I don't disagree with the spirit of your argument (the "Iron Wall" tank is fun), but I wanted to correct the math on that.