There's a great line in George Blackburn's trilogy (Where the Hell are the Guns, The Guns of Normandy, The Guns of Victory) about this. Apparently by the time the got to Holland the Canadians had been liberally incorporating captured German weapons and equipment with such abandon that with "...Canadian soldiers wearing captured German uniforms and shooting captured German weapons that it became very difficult to tell who was who in the dark without a program".
Or words to that effect. I loaned my copies out and never saw'em again :/