Heh. My take on Ueshiba is that he hounded Takeda to get all of the goodies.
Body size notwithstanding.
Dunno what the dealio was with big guys getting jujutsu, little guys getting aiki. From my training in jujutsu, I can see how small folk could be at a big disadvantage trying to apply joint locks, chokes etc. on larger opponents - they'd have to find a way to bring down the big guy to their height level to apply those techniques, which means having to add on stuff to their attack and thus reducing the efficiency. Not just that, but it's damned hard to get the leverage on a large person's joints to get an effective lock in. Been there, done that. Had it done on me. You get to see the weaknesses as you attempt to do techniques and as training partners of different sizes try to do them on you.
Big guys tend to use muscle a lot, which is anathema to creating effective aiki.
So, Takeda may just have been figuring "Well, the big guy doesn't really need aiki, and it's harder to get him to relax enough to do it anyway."
Just a guess.
Meanwhile, Takeda famously said that Daito-ryu could be taught to women and children. I doubt that he was referring to the jujutsu aspect. He was saying that aiki is the tool for the small and (relatively) weak.
Too, aiki isn't a miracle pill or a magic spell. It's just one component of what were larger martial systems back in the day. A number of koryu systems taught aiki as just one aspect of what might have included sword and other weapons, jujutsu, and other physical skills. Aiki was meant to be a "performance enhancer" that one could apply to already-effective systems of armed and unarmed combat. Alone, those systems were perfectly fine. With aiki added, they become even more powerful.
My two yen.