Interesting question, Azizi. When I was a kid in Detroit in the 1950's, we all knew "Sound Off" from the Vaughn Monroe record - but we sang it as close as we could to what we heard on the record.
I didn't really have any other contact with military cadence counts until Uncle Sam gave me an 8-week, all-expenses-paid seminar on the subject in 1970 [grin].
Seems to me that kids during WWII would have been more likely to have done this. Maybe some of our "better-seasoned" participants will have something to contribute.
-Joe Offer-