One game featuring a German with extendable robot arms is a thing. Two is a coincidence. But three? All starring in games developed by Japanese studios? OK, three is a pattern.
This post over on GameWTFs, highlighting ten cyborgs starring in Super Nintendo games, contains not one, not two, but three Germans with robot arms.
The first is probably the most famous: Brocken, from World Heroes. The second is Helmut from Street Combat. Note that both of these guys are about as Nazi as you can get (though Helmet may be a full-blown robot. Hrm.)