I think there is an easy line. We know what should occur with certain parts of the body. Ears should be able to hear so when they don't we know there is a problem.
There isn't a height in order to function properly or something like that. If somebody is 5 feet or 6 feet they are still capable of having their whole body function. Yes, they may have issues due to their height but their body still works correctly. (Extreme heights, both tall and short, may cause issues and there could be conversations around that, but within the normal range there isn't any sort of function of the body that doesn't work)
It's crazy to me that we even need to explain the difference between variation in height and a non-functional organ. I don't know if people are just so open minded that their brains fell out, or if it's some new idea where everyone gets their own personal perception of reality and nothing is real, maaan.
There isn't a height in order to function properly or something like that. If somebody is 5 feet or 6 feet they are still capable of having their whole body function. Yes, they may have issues due to their height but their body still works correctly. (Extreme heights, both tall and short, may cause issues and there could be conversations around that, but within the normal range there isn't any sort of function of the body that doesn't work)