Humming Black Dragonscale versus Ashvane's Razor Coral BM hunter

The Ashvane’s Razor Coral (445) is still one of the best trinkets and the Best in Slot of AMR suggest replacing it with Humming Black Dragonscale (460).

Nevertheless the simulation in AMR also shows that Ashvane’s Razor Coral (445) is better than Humming Black Dragonscale (460).

How come that the Best in slot gives a different outcome than one can conclude from the simulation?
Is the Best in slot using the same calculation as the simulation?

I would have to see the specific case, and see how much different it is. Do you have a link to the simulations?