This buff has not scaled at all since it was implemented. Both the Melee and Flurry Multi is way to low for current content. I suggest 10 Melee Multi and 5 Flurry Multi as a change but set it up to scale with level so future changes won't be needed.
I agree, its garbage in its current form, i never actually use it, since it disables AoE auto which i like to use with Reinforcement to help me manage multiple mobs
