The funny thing is, they were struggling in Tier 11 along with Shaman. It was polarizing. That same patch that brought the MTT nerf also brought Tranq down to 3 min from 8, which was a pretty big boost to Druid HPS. Their HPS was already fine in Tier 11 (they wanted utility iirc), but with that and the heavy amount of movement in FL affecting them very little, their better at the time Harmony mastery and their near endless mana, they ended up top HPS on most fights by a fairly wide margin. Even the worst fight for them that tier (Baleroc, with no AoE damage and heavy spike damage) they were 3rd in HPS.