Good point. But Tacitus was part of classical civilization, not Western Civ. Classical civilization was one of the two parents of Western Civ.
BTW, as with many (perhaps most) Westerners who glorify other societies, Tacitus’ main reason for praising German society was to use it as a convenient club with which to bash his own Roman society. Thus his book really tells us more about Tacitus and Rome than it does about the Germans.