On the slide you saw three or four flight attendants. The reality is that in a crash, some of those flight attendants will die or be incapacitated. That's what the U.S. NTSB said for a study of redundancy, that there may not be all the flight attendants when that plane finally comes to rest; then you do with what is left over.
It is factored in, then, in the sense that it provides a margin of error in the event of incapacitation or death. I believe that is why Transport Canada staff decided to go with one flight attendant per floor-level exit on the wide-body plane. They realized that coverage was needed for the A340--to go back to that slide--rather than the A320, as you can see. That's why Transport Canada said that one flight attendant per floor-level exit was needed.