Re: Traditional Suburi Training?
Aiki-jo and aiki-ken are learning aids for taijutsu. They are not about learning the direct use of the weapons.
The suburi are to learn basic movements. Suburi #1 is to learn the basic shape of the overhead cut. The bokuto is down the spine to check/learn centerline.
It's the same sort of thing that my first baseball coach had me practice hitting from having the bat "cocked" extra far and the lower part sitting on my shoulder.
I.e., it's a pedagogical tool. One may agree or disagree with its effectiveness, but one should not read any more than that into it.