For Sigmascape V2S, unless they changed something with the recent hotfix patch, if you only had one tank the Goddess Chardanook wouldn't do auto-attacks on anyone (MT included). The group I raid with tested this out week one but have since decided to do our weekly clears with both tanks. For those interested I did indeed solo tank it week one as DRK and did fine (though a bit oversafe with Grit).