I was always led to believe that the 7 suburi cuts with the bokken are not meant to represent "realistic Swordsmanship"
The 7 suburi is not real swordsmanship per say. Think of it as a list of cuts that can be made- sort of like listing the throws/projections of aikido.
Simply listing them and knowing them does not necessarily means you can do them. It is all in the application of technique- that is the real swordsmanship.