Fervor isnt that useful for BM at all. BM is the least focus starved spec of the 3. Between havign 20 more focus and the insane focus regen the pet gives AND bestial Wrath adding 50% focus reduction, its pretty nice. Readiness is gonna be the go to for BM imo because of double Rapid Fire/Bestial Wrath/Lynx Rush(if you take it for burst).