The difference is important. Hit points are just abstraction. Falling a 100ft and being able to stand up and dance a jig is a fictional game outcome.
It doesn't matter what rules got you there. If it's a game artifact and not a reflection of what the reality is supposed to be in the setting it seems you have a problem with Sim.
In D&D it might be escalating hit points that make a character completely indifferent to a crossbow pointed at your face - in Warhammer it may be that you are a Dwarf with a ridiculously high Toughness. It doesn't necessarily matter how you got there, if you are trying to simulate a world (or genre) where people should be afraid of crossbows aimed at them you have a problem.