Hopefully they will be too. But on what basis is there the charge of inconsistency? Without knowing full details of either of the cases I can still say with confidence that they will be different, and that this will likely lead to different sentences. This is consistent with the law having general rules that are then applied to particular cases, taking into account the specific circumstances. While this may lead to "inconsistencies" in the surface, is it really that inconsistent?
There are benefits I suppose, to a system of "Murder? - 40 years", etc., in that at least it would be simpler to follow. But there are different types of murder, different causes, motivations, extenuating circumstances, and so on, that could all affect the case. The sentencing, I hope, takes this into account. Hence the "inconsistencies" are only between cases, not in the system as a whole.