Sergals are known for their regional, racial variations in appearance like height and color differences. However, from 50RC onwards, nationality starts to take up a greater importance than race or subspecies because of the sheer amount of mixing gene pools. Gold Ring in particular is a great example, which is full of mixed Sergals.
The Southern subspecies has many black and grey sergals, and not all of them are as short as the original Southern subspecies members. That being said, there still are Nobles (the pure Southern Sergals) that do not exhibit any of the hybrid traits of the North or West, maintaining their original deep brown tones in color.
For learn about this more, please read "Height Ratios" section in Wiki article of Sergals: http://vilous.net/wiki/Sergals#Height_Ratios