As a Tanksin I will share what my guild does for HM EC on the tanks. I hope that it helps.
I tank Firebrand - we put the other tank we've picked up on Stormcaller. We do this because as a Tanksin I can solo tank Firebrand w/o help from the other tank. No taunt needed. This in turn allows the Stormcaller tank to focus fully on his tank using all his taunts a what not to hold agro.
By rotating CD's I can handle Firebrand quite easily. For the first Incinerate Armour I will Force Cloak, this cancels Firebrands cast and it will start recasting on a DPS. As the cast bar is going I will taunt and take back agro. About 1 minute later we see another Incinerate Armor. For this one I pop Deflection + Armor Adrenal along w/ Dark ward. I have never died at most I will take 1 hit during this phase. Force Cloak will be up by the next incinerate armor.
As a bonus if you have very good DPS this method works even better because soon after incinerate armor, if enough damage is done, you will be pushed into a Defensive Systems phase with taking no more then 1,2 hits from Firebrand.
Best of luck w/ progressing...
I have talked to some people and this method does not work with their group composition but as I said - this works very well for us.
you can force shroud thru it too, although the tank swap method works better in my opinion.