Android 17 and 18 are cyborgs - they retained their human personalities, free will, and ability to reproduce. I don't know how much of their body is actually changed, but it can't be that much if they can reproduce.
Though personally, I would classify anyone that was fully human before as cyborgs even if they are fully mechanized now, since they still have the fractured identity of a cyborg. Are the MK cyborgs fully lobotomized or do they retain any hints of memories or personality?
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this is a world... where birds eat horses