... my response to Mister Carsten as well.
You posted a clip which has no connections to aikido or daito ryu as far as I know. Thats what I just pointed out.
So I don't understand, why you find this clip interesting and what it has to do wiht aikido.
I don't see any connection from this clip to your question.
We don't have challenges, but we often train together with pracitioners of other martial arts. That is very interesting and has made aikido much more "attractive" in our area.