Identifying all the fingers seperately

In order to control each servo we have to identify fingers separately(thumb, index, pinky, ring, middle). The sdk assigns an ID to each finger however this randomise always. So I did some research regarding this and most of them were suggesting to identify each finger by taking their lengths and the angle between palm and the tip position.

However I managed to identify each finger by sorting the x coordinates. So the left most finger is the Thumb, then index and vice versa.