For instance I think if you remove the slaves edge from an orcs arsenal the relative value of oily skins SKYROCKETS. (it is less about getting specific mobs and more about the geographical locations of mobs you can enslave without the edge that are useful at the highest ranks)
I also think if you are not a shig-ru it makes a big difference (not all orcs have some form of dam redux or a skill like rush which overcomes non-laggable people and facilitates getting behind the slave strategies)
I think orcs would be fine without access to it if they cut the exsanguite timer by 50% or 75% but barring that I would rather see more sources to gather blood, not less.