I did TBL paragon with a ToV ice encrusted/snowbound geared group.
I just started up a new toon so I’ll run him through it real quick. With fellowship fires I can avoid all the flagging and sub quests and do strictly the hero missions. I can usually do it in a single day if I don’t get interrupted.
If the zerks stay at range and use throwing to range him down, that would work but take a long time. If they go in to melee range, they will need heals to stay alive. A completely full melee group is just boned by this mission.