I've done ToTing in Talos with below-30 Tanks and ALL of the Big Ones are Three-shots even with full enhancement (no sets). Been having to *run* to Citadel (got Luminary STUCK in the Community Service Kiosk during one of the fights on Everlasting) to take them down.
And even then, Luminary and Citadel *have a hard time* taking them down.
While player is on *tanks* who are supposed to be 'the most durable'.
At -1x1.