You bring up a vaild point about stances and how they've traditionally not worked very well, but there's a big difference here because these stances have little to do with DPS. This concept for DT is essentially turning all your single target spells into AoEs. This essentially means you get to use an AoE Physick when you need it, AoE Broil/Biolysis/Miasmolysis instead of needing Art of War or Bane, and essentially allows us to have 1 action instead of several.

ET as I've designed is supposed to turn Physick into a "Physick II of sorts" which inandof itself wasn't really enough to justify it, even if it could also influence this concept for a high CD GCD heal in Epiphany, which is why I ponder if it could be a way to turn GCD actions into OGCD actions to consume resources like the Fey Gauge, but Aetherflow could even make more sense.