You may want to rerun your numbers as they have nerfed the coefficient back to around .71 based on the nature debuffs now provided by druids/warlocks. However, they have admitted that this creates a problem for solo play and 5 mans where those other two classes are less likely to be in the group and are working on a solution.

Blue post admitting nerf.

Blue post saying they are working on the solo/small group aspect.