The 'aiki-in-yo-ho' is not something that is expressly taught. Its not like hey guys come over here and we will do some aiki-in-yo-ho. It is something you live and you have to work out yourself.
If you look at what Amatsu Sensei said 'Samurai did not do solo training, they always trained with their teacher. Solo training is a more modern approach created for women and children'. That is something you have to work out.
Judo had solo training, If you look at basic things like shizentai, that is the foundation of everything in judo.
As an ex judoka I was fortunate to meet some great in the Judo world, eg Anton Geesink , Kenshiro Abbe , Saburo Matsushita, Kisaburo Watanabe and my own teacher Tam [Thomas ] Mc Dermott.Mr Mcdermott despite being 90 % disabled was a great judoka.In the 13 years I trained with him I never saw anyone ever throwing him.Now while I accept that shizentai is a very important aspect, imo the key to success in judo/ aikido is where/when /how.By that I mean where - correct positioning of yourself in relation to your partner,When , the correct timing executing the waza again in relation to Uke/How -choosing the appropriate waza suitable for the situation.
I also feel that the unbalancing /destabilising uke is also of major importance.A combination of good posture, a flexible mind and body coupled with a strong spirit gets results.All the best , Joe