If you had three identical wheels and a fourth one that was smaller than the others would you mount all four on your vehicle? Seems like a ridiculous idea doesn't it? Would you be surprised to learn that your body faces similar issues from time to time and has to decide between the equivalent of mounting four different sizes of tires and risk getting into an accident or to abandon the vehicle altogether. In other words, the body will attempt to create a disease and operate sub-optimally rather than shut the body down.