Parson mentions he's been explained that a short fall might end up with a unit croaking or geting incapacitated at random.
However, i don't think that makes erfworlds rules seem more absurd than our own world...
Theoretically, anyone could be careless, trip over, hit his head on the pavement and loose half his teeth or be incapacitated (or worse) just by walking the streets, and that's just as random, even if the heigh of the fall is insignificant.
I find the fact that erfworld's units falling from 10 stories height might potentially not only survive but be in condition to stand up and wage war makes falls in erfworld sound much less serious than the ones in our world.

