...I will open this thread with that statement and add a little more in the next post.
As to the usefulness of sutemi waza, I have some examples and I want to put out some reasoning as well.
As to the danger of using sutemi with multiple attackers, I saw in an old thread on aikiweb a post by Graham Wild of the Perth yoseikan group (in 2001). He pointed out that aikidoka train in pins, which would be dangerous if not impossible to apply in a multiple attacker situation. So sutemi waza is not less realistic or useful than that. If anything, knowing that one cannot stop and control an attacker, it points up the vital necessity of ending the encounter with a single move. And sutemi waza is quite good for that. Plus, the way we trained, we learned to roll up on top of the opponent or simply to roll up to standing after sutemi. So while it would definitely be dangerous to go to the ground with multiple attackers, there are technical ways to "run the risk".
Next, Mochizuki Sensei told a story of actually using sutemi waza in wartime.
After Japan surrendered, he remained in Mongolia for some time (or in China) as a communist hunter. He never did take a liking to communists. But supposedly, Mao had a price on Mochizuki's head. Anyway, one day, he was eating at a restaurant and the waiter who brought his food was different than the guy who had taken his order. And under the tray, he had a pistol. He told Mochizuki to get up and go with him, but Mochizuki said he wanted to eat his meal first. The guy pushed the pistol against his body and Mochizuki rolled out of his chair, grabbing the pistol barrel, and pulled the guy over and dropped him. He then shot him with the pistol. Someone outside began firing into the restaurant and Mochizuki returned fire. He finally got out of there and escaped on horseback. So sutemi waza actually worked in an armed encounter during wartime.
In another story, he told of a Frenchman who was already very competent in judo when Mochizuki arrived in France. The guy wouldn't train with him, but criticized him to other French judoka and one day appeared at Mochizuki's apartment and demanded that they fight. Mochizuki pointed out that they were on a concrete (or stone) sidewalk, but the guy insisted on fighting right there. So Mochizuki accepted and the fellow began attacking with judo. Mochizuki said the guy had good timing, good rhythm, good movement and good technique. But Mochizuki caught him with uchi mata gaeshi (inner thigh reap), threw him up into the air and came off his own feet as the uke went over his head. So the uke hit the sidewalk flat on his back and immediately after, Mochizuki landed on his stomach. So that was a kind of sutemi waza from a standard judo throw. And it hurts like the devil when nage does an aerial ukemi and lands on your stomach. He almost killed the guy. But he picked him up on his shoulders and carried him up three flights of stairs and nursed him back to health (he had training as a bone-setter and massage therapist). No one heard from the French guy for awhile and the word got around that Mochizuki had killed him, but he finally recovered and became a devoted student of Mochizuki's. So there is a sutemi waza (more or less) in a self defense situation.
And from my own experience, a couple of years ago, I found myself on the edge of applying sutemi waza on a sidewalk in a self-defense situation.
My neighbor had a lawn guy who used my yard as a turn-around when he cut the neighbor's grass and I often came home to find a big, ugly gap in my lawn. So I put a political campaign sign at the property line and figured that would get the message across. But it didn't. I once more came home and found my sign had been taken down and tossed across the yard. And the guy had come into my yard and gapped it up for his convenience in cutting the neighbor's grass. This time, he was out front of the neighbor's house in his truck. Since the neighbor was also out there, I went over and said, "Excuse me, but whoever you've had cutting your grass has been coming over into my yard and making this big, ugly gap." And the guy in the truck said, "I cut that grass. I'm the one you want to talk to." And then he started lecturing me on how I should come to him respectfully and be nice to him, though I had not even spoken to him at that point. And the next thing I knew, he was out of his truck and coming at me. I sort of ignored him and kept talking to my neighbor. I said I put the political sign at the property line to mark it, but this guy took my sign down and threw it to the other side of the yard and cut past it. I showed the guy the property line and he started cursing. And then I saw where he had ridden his lawnmower up on the sidewalk and cut another weird swath in my grass 15 or 20 feet from the property line. I said, "And what's that?" He said, "I did not do that!" which was ridiculous, but he was getting really angry. My four-year-old son came up to me and I was afraid this guy would do something crazy and my kid would get hurt (I'd also been to the eye doctor that day and my eyes were dilated, so it was a touchy situation). I told my son, "Go back in the house!" and he did. And then this guy, who was maybe 5'10" or so and maybe 220 (I'm 5'11", then about 190) got right up in my face and I stood toe-to-toe and eye-to-eye with him.
Now, you could say this was a violation of aikido principle to let him get that close (not to mention the way it all had played up to there...but it shows that things in the real world happen suddenly), and that was how it had evolved. If I'd started moving around or put up my hands, witnesses could have construed it as some kind of fighting move and say that I started "taking a stance" with him. But I just stood on my property in shizentai and held my ground and he got in my face. Still, I felt pretty comfortable with my options. I also realized that I could not give this guy two chances to hurt me. I could tell that, if he went for it, it was going to be a tornado of fists and head butts from inches away, and I just made up my mind that if he tried to roll over me, I would let him. And he would have landed head-first on the concrete.
We stood there eye-to-eye for several seconds before he backed away and apologized. And I made conciliatory remarks to him and he left. But just for a moment, I thought it was going to go in an unfortunate direction, with a serious risk to my life and, potentially, to my family. I never made aggressive remarks to him. I was talking to my neighbor and he jumped in. The whole thing was over in 30 or 45 seconds. Out of nowhere, coming home, at my own house, in my own yard, after a visit to the eye doctor.
At that time, sutemi waza would have really been what they call it: "superior" technique. I rather doubt that any arm-twisting kind of technique would have been effective because he had powerful arms and would have been difficult to control. But to take him straight across with his own rush...it would have let him put all that power right into the sidewalk with his head. I'm just glad he finally realized what a weak position he was in, all the way around. And I hope I never find myself in a thing like that again.
But in a position like that, I have full confidence that sutemi waza would have been the safest and most effective thing I could have done...though possibly fatal for the attacker.
Let's all be careful out there. Huh?