Re: "Aikido instructor shared skills with soldiers, Steven Seagal"
One thing I have learned about Aikido history, the way people say it was and the way it was are often very different. Of course, unless we have a time machine, there is no way to know exactly what happened.
Iwama is and was a Japanese rural farming community. Anyone who was involved with the farming would not have been able to spare the time for much training. Saito Sensei worked for JR, I believe. He worked non-stop for a week or so and then took time off a week or so to be with O'Sensei. Hirosawa Sensei was a relative of Saito Sensei's.
Another important element is that O'Sensei was considered an odd duck by the locals. In a rural farming community in Japan, that is the kiss of death. Remember, Morihei Ueshiba was not a local. In fact, he spoke with a strong Wakayama dialect that would have been difficult for the locals to understand.
In my understanding, when O'Sensei was alive, there were a few people crazy for training (the sensei mentioned above) and a bunch of local kids.
Iwama was largely used for training camps (gasshuku) by university clubs and Self-defense Forces clubs (via Isoyama Sensei). Also, some of the other Shihan stayed there for extended training, Shioda Gozo, Chiba Kazuo, etc.
Of course, this is all my understanding derived from the sum total of my experience. Others with a different experience are naturally going to have a differing understanding.