I've seen these guys, and they are really neat. Every face and uniform is different. Some of these soldiers are definitely not "Chinese" -- they look more like Turks.
This was the best part of my tour of China in 1983, and not too many people go there because is is off the beaten path and expensive. I highly recommend the ruins at Xian where the soldiers are being unearthed.
My sister went there, she was as awe struck as you. I've seen them in magazines and TV. Each is unique.