Reminds me of an article I read lately. A guy who was invited to join the monks going up a mountain to a pool and waterfall to do their meditation. He was told to bring a walking staff.
He turned up with a jo and the leader of the monks recognized it and tild him it was an aikido jo and not a walking staff and proceeded to tell him how to walk up the mountain properly. Even the way to do so was fascinating as it involved pressing your big toe down on each step to serve as a reminder in every step to be here spiritually in the present. He also found that the monks blew these konchos on the way but actually each time they did it they were in a certain posture. The same as the stance in Aikido.
Anyway, later, after the meditations the monk proceded to hive him a lesson in the jo. Turns out he was taught by Hikitsuchi Sensei. Funny thing is, and the whole point of this post, that the monk told him how once if Hikitsuchi thought Aikido would benefit the other monks. Hukitsuchi told him that It was merely a spiritual path where the techniques were just an added bit of fun so to speak and that's why others didn't understand O'Sensei. He also said that the monks were already doing it for they were already on the same path.
Like this story! Not many people seem to be aware of the relation between Aikido and Shugendo. And there is not much written about it either, as far as I know.
Is that article that you are quoting still available or to be found on the internet?
Greetings from the Auvergne!