Against My Better Judgement
Maxwell - it's not common sense. It's closer to nonsense. The problem is you have no historical grounding. To say that if a ryu was in Aizu so Takeda must have studied it displays a lack of knowledge of how ryu were taught. For one thing, there were otome-ryu. There were machi-dojo. There were ryu associated with bushi, others with goshi and still others with commoners.
I cannot recall the number, but Aizu-han had a number of ryu. It may have been over 100. Asayama Ichiden-ryu was considered a plebian ryu, associated with low-class individuals (goshi) rather than bushi, so that doesn't fly. Tanomo, in particular, if he did ANY martial art, which is considerably in doubt, would no more likely have done Asayama Ichiden-ryu than the Swiss Guard would start doing capoiera.
I trained in Tokyo almost as long a period as Takeda trained in Aizu. There was Yagyu Shinkage-ryu, Itto-ryu, Chokugen-ryu, Tendo-ryu, Tenshin Shinyo-ryu, just to name a few, all within bicycle distance of my house. It's common sense that I studied each of them?????
I looked at the thread - and lets consider the source - Ueno Takashi's associates have maybe a <little> more creditability than the Bujinkan, but barely - they are part of the same circle. The writer didn't even have the name family of Takeda's grandfather correct - Kurokichi Dengoro. And he wasn't aware of the rather extensive documentation on the arts he actually studied.
Now, a rather well-known author wrote a book called Hidden in Plain Sight, which wrote, in some detail about Kurokichi - and the actual martial arts he is ON RECORD as having learned. Asayama Ichiden-ryu is not one of them. That well-known author also went through the martial arts that Takeda is known to have studied - and there is no mention whatsoever of Asayama Ichiden-ryu.
Back to that thread - a number of people with connections with Daito-ryu, consider the possibility of a connection, and the best they come up with is some speculation that AI-ryu was used as a template for the mokuroku - this has nothing to do with the waza. In other words, MAYBE since Daito-ryu techniques were taught haphazard, the Takeda's organized all the waza according to a pattern already laid down. Nathan Scott, who has read both mokuroku, goes at some length to establish that, even on a template level, the organization is NOT similar.
In short, there is no evidence. And oral tradition has to be more than "some guy said." It doesn't conform to any known history, to the social structure of Aizu, and to the actual organization of the mokuroku.
Ellis Amdur (If you want some real history, I might suggest purchasing that well-known authors book)