I have different opinion, I heard u run sakuralisk with malwing + maple or maybe its bcoz u run it with plume and soral Thats why it work really success. Maybe u right tier B its to low for her.
I am believe sobeking around tier S or S-
But for malwing I need specific team to support her , reckless timestrike rarely oneshot to make her get a kill. Her value its really different like other S tier monster