Strangely..
..their won-loss record is lousy. The Hessians got their asses thoroughly kicked at Trenton without killing a single Colonist, changing the course of the American Revolution. Napoleon I ran circles around them and the Austrians, the Franco-Prussian war was ultimately a draw, and we know the rest.
In terms of a football analogy, the Germans are "Air Coryell", and tend to lose by scores like 42-38 - if you kill enough of them they will eventually stop making suicidal charges.
-drl