If you never go below 30% - then Whitestrake is uselessIf you do go there every 15 seconds, then consider this: 840/0.18~4667. Which means 840 damage shield is equivalent to dodging exactly 18% of damage with Hist Bark if incoming damage was 4667 within 15 seconds. If it was more than that - Hist Bark is better. If it is less or equal - damage shield is better.
Also, dont' forget that you can dodge DoTs, however - damage shield will absorb them. I guess, both sets are viable. It's just that there are situations when Hist Bark is better and there are situations when Whistrake's is better. You might carry 2 sets and switch between them or you might choose one depending on which situations are handled better by your healer (then grab a set that will make up for heals in other situations).
Also, I dont' know why you would use it as a tank now, when there's undaunted bastion(I think?) that gives you 1240 damage shield, which is much better.If everything works the way it logically should work - they do stack. However, your total dodge chance is not E+H.Lucas.interlichnrb18_ESO wrote: »What if I use Evasion with Hist Bark? does that stack?
T=1-(1-E)(1-H), where E - evasion's dodge chance, H - dodge chance granted by Hist Bark.
I didn't check it experimentally, but I run both HB and evasion and it feels like I dodge more often when evasion is active.