Do you know who made the original international regulations?
Step forward K Chiba, when he was head of the fledgling Hombu international department. This was in the mid 1970s, after he left the UK and returned to Japan. The international department was created at much the same time as the IAF was founded and the one was meant to be a sort of mirror image of the other. K Chiba was head of the international department and was also the main activator of the IAF. (I think that Ellis has some stories about how K Chiba ran the inaugural IAF meeting in Tokyo in 1976.)
I suspect you have no idea of the internal machinations going on within the Hombu at the time, over how to deal with the vexed question of international aikido organizations--as organizations, not as the personal dojos or fiefdoms of individual teachers.
Remember also that K Chiba committed the unpardonable sin of resigning his overseas commission in the UK and returning to Japan. So he had to rebuild his standing within the Hombu. As a result, the original international regulations were a 'committee' document, full of subtle ambiguities designed to appease the concerns of a particular Sensei or faction within the Hombu. (How do I know this? Well, when the regulations were revised in 1988, I was asked to make a new English translation, with the changes incorporated. So I had the job of translating the ambiguities of Japanese into clear, sharp, legal, English.)
Yamada Sensei was happily rolling along in the US (I know, because I was there at the tine), when suddenly, overseas teachers were asked to approve these new international regulations. The Americans were not very happy at all and were even less happy with having to create an organization, to be called the USAF, which would then join this new super-organization, to be called the IAF.
So I think there is no wonder that neither the Hombu's international regulations, nor the Rules for Shihan (which, by the way, no longer appear on the Aikikai's website) are very clearly expressed, as Yamada Sensei states.
PS. Since I wrote this post, I see that Dan has posted some questions. Since he mentions me in his post, I will attempt to answer his questions and this might also throw more light on some of the issues raised by Yamada Sensei.