There is no choice.
You tank focus and then you marked, so unload that focus into a vulnerable window. That's all you do the entire fight long, spam arcane shot for focus, use a proc at a sufficient amount of focus, and then followed by 2 to 3 aimeds. More aimeds during BL and other haste effects.
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BM doesn't feel clunky, it's as smooth as it's ever been but the problem is still that the pets can be quite unresponsive or the entire opposite and spas out.