Mike, you're right about lack of info, but based on the bit we have, of course it is fun to speculate.
Two things strike me as interesting here:
1. Takeda, being illiterate, may very well have NOT seen the bigger picture you are talking about, despite any really amazing skills and sophisticated usage he may have had. He knew his own training history, and he knew his innovations, but I wonder how much of the older history he had exposure to. Conversely, Ueshiba probably had the history before the skills, and when he met Takeda, it started to come together. In this possible scenerio, the tying together of old history and personal abilities would really have happened post-Takeda.
2. It has been suggested that Takeda really did a lot of exploring and innovating to piece together the abilities he had. I think it is possible that he really scraped together info that was almost lost, and ressurected something, rather than carrying on a strong tradition.
Kind of fanciful but it would mean that there is a bit of "new growth" and discovery in the history of aikido, even if it did end up replicating what other people had known for centuries.
[edit, overall I agree regarding the aiki arts being placed in a bigger picture. I just like this possible aspect in the history of 'rescue' of info that may have been on the decline. It.... resonates with me.)
It could have happened like that, Jonathan, but even though we westerners have fairly sparse information, there are plenty of indications that ki/kokyu skills were available (but hidden) at and before the time of Takeda. In a number of then-current arts. And as I said, the idea of "blending" or "combining" as one with an opponent is something touted in the Chinese classics. So "Aiki" (or whatever name you want to call it) was there, in various configurations.
BTW, note how Ueshiba knew enough to relate these skills to already-existing classics. Should we say that he was slighting Takeda by doing so or should we say that Ueshiba understood that these skills were not new and that they have been around a long time.... and he was just acknowledging the obvious, no slight intended? To put it another way, Ueshiba would have looked ill-informed if he'd actually said that Takeda originated "Aiki". Ueshiba knew better.