As one of Canada's Nationally certified umpires as well as a clinician, I must say that I am completely confused!
At no time have I ever seen, nor heard of an official being 5-7 ft. behind a catcher, and I know for certain that it is NOT a practice that is taught or advised in any manner.
We do advocate the 'Slot', 'Scissors', and 'Box' style positioning, but also try to impart the importance of being relatively close to the catcher, so that the ball doesn't disappear behind him.
In fact, just last year, there was an umpire in my local association that swore that he got a better view of the strike zone from 3ft. behind the catcher. While his zone was acceptable, he had a great deal of trouble being consistant at the bottom of the zone. Myself, and a few of the other senior officials spent a good deal of time with him in the cages and showed him that he could get the same view, AND include the bottom of the zone if he moved closer. I am happy to say he is now reformed, and one of the most consistant umpires in our association...now if only we could get him to master the pivot....
Anyway, I can assure you that Canadians are NOT taught to be 5-7ft. back- I assure you!
Bainer.