Your tank will also make a difference. Paladins can sprint when making their mob train since they spam flash to hold hate initially, whereas a warrior needs their tp for overpower. I find usually i70 is a pretty solid number to go by for any role in speed runs. Speed runs are really about how much raw heal power you can push, so if you have a really strong gasp of healing, you can get by with less. Alternately, if you dip into the red zone a lot, or can't keep up the tank, overgearing will go a long ways to reduce healing strain