This is a nice size 31 cm, pottery Guard, grey pottery with red pigment remaining. A figure from the same mould is depicted in the book; China: at the court of the emperors,2008.
So the dating can be quite exact, because the figure from the book is found in the tomb of Yuan Shao, dated 528, in Luoyang province.
The Northern Wei dynasty is dated 386-534 aD. The tomb of Yuan Shao held over 150 pottery figures, this particular one a bit bigger than the others.