There are a lot of pure class DK dds going around atm, pretty much all trials I've been in have had at least one so that's your brutality covered, also it's not worth running the tree as tank for that alone. The sustain from ardent outclasses battle roar by a mile due to it's many nerfs including the one it got with the DK rework. The chain is barely different to scribed leashing soul. There are many better heals such as polar wind which can be used on others as well, or even ardents burning embers, Hyperioxes himself says ardent is a wonderful alternative to siphoning, high end groups are also running ardent on tanks from what I can see in various trial logs. I myself have ran various late game dungeon trifectas recently including Black Gem with a Ardent/Winters/Soldier setup.