Duilliath

Do you have Survival of the Fittest ? 415 defense means nothing with a wrong spec.

Tanking 4pulls isn't a huge problem once yer used to tanking. When learning the ropes, bring some CC so you only face 2 at most. Only SH and SL have larger packs, from the top of my head.

//edit: My understanding of Armor Cap @ t4 level was that this was with an Inspiration/Ancient Fortitude bonus.

//edit2: Lacerate was changed to have 60ish damage on hit. This enabled it to deal threat on Bleed Immune Mobs. It's also the bit that deals most threat, so the lack of a dot ticking don't make a huge difference.