Thoroughly enjoyed the first video. Very explosive, and I liked the technique shown.
Don't know what to make of the second vid. Greg was trying to be nice I suppose, but yeah....
BTW, here's some submissions from knee on belly;
Is there some reason they couldn't be translated into Aikido?
I put the first video in there to show the type of grapplers Greg usually plays with. He can toy with most of the instructors he meets in those exchanges, unless they're prodigies like Loubersanes or Saladdine Parnasse.
Given the difference in size and grappling level (Tamaki doesn't grapple and trains aikido as an armed martial art, something I don't necessarily agree with) I find that Tamaki fared pretty well (way better than the Rokas guy). On the one hand, he didn't submit Greg apart from a fingerlock that caught him by surprise, but we're talking about a guy who can defend against Loubersanes. On the other hand, Tamaki successfully defended most of the time and recovered nicely from the failed rokkyo (you might know this as ude hishigi hara gatame) which left his back exposed. Most importantly, in the debrief Greg commented on Tamaki's surprising power, which is a direct result of good aikido training. He couldn't break Tamaki's posture or move/uproot him and his "wins" in the sparring came from the overwhelming difference in grappling technique and tactics, which was expected.
As for the attacks from KoB, there's no reason they couldn't be brought to aikido. We have bayonet stabs, everything goes.