The TES signs do not exactly correspond to the signs of the Western Zodiac. They correspond to specific months, or "seasons" (except for the Serpent, which has no season).
The months are listed in order, so Morning Star corresponds to January, Sun's Dawn to February, and so on. I got the information about the procession of the months from
here.
If you're a Scorpio, you are either born under the Tower (if you were born between the 24th and the 31st of October / Frostfall) or the Atronach (if you were born in November / Sun's Dusk).