They may have outgeared it or maybe it was a later season. SL S1 tanks were so fragile that the meta was to kite.
They always do this and say it’s to make things less bursty and it 100% never is what actually happens.
If you want things to be less bursty you can’t increase damage by the same amount as you increase health. You’d have to increase health and leave damage where it was and possibly reduce at least the higher-end healing values.
As far as the original topic goes, they need to re-design DKs and DHs if they don’t want their health to yo-yo. Blood shield should be changed to be more like ignore pain. DH could use a stagger like mechanic maybe converting some damage into a fire DoT and rather than cleansing it you counter some of it with your own self-healing.