Defense debuff stacking - help me understand!

[Guvnor]

Do Elemental Defense Debuffs and Regular Defense Debuffs Stack? Why use them together? For instance, Grimm, Tiburtus, Gormek, Buddy or Wilbur with Guardian Jackal, Falcon, Panther, Arthur, Frida, Nordri, or Evelyn. [MASTER]

@Kerridoc

To the best of our knowledge, the debuffs stack multiplicatively.

Example: You take Grimm (34% general defense reduction) and Jackal (-54% Holy defense reduction). The target’s effective defense is (1 - 0.34)*(1 - 0.54) = 30%, or a 70% defense reduction.

Remember that this goes into the damage calculation inside the exponent. The general formula says expected damage is proportional to (Attack / Defense) ^ 1.35. So a 70% reduction in effective defense basically quintuples the per-tile damage.

This multiplier is damped down by an unquantified but confirmed tempering of the damage as the ratio of attack to defense gets very high. You probably won’t see the tempering much unless you have big stacks of the color.

Also this thread:

What order should I use defence debuffers?

I couldn’t find an answer to this, but happy to be redirected. So, clever people, if I have two defence debuffers, or a defence debuffer and elemental defence debuffer, is there a rule of thumb about the best order to use them? For instance, in the Trial of Smash It (or whatever and barbarians) I take Grimm and Gormek. I assume that the best cumulative damage is a lowish hit by Gormek followed by a much higher hit by Grimm, rather than a moderate hit by both. But I haven’t tested it. Simila…