Are we talking about lock-flow drills here?
I use these as instructional mnemonic aids to remember techniques, like a alphabet of kansetsu waza. I have one that goes through ten locks.
I certainly do not expect that the first one won't work.
having said that it also makes a good demo.Shows a range of possible jointlocks.
But: In Judo, we do transitional flow gorundwork, similar to this. Now in a tournament, when I slap a Kesa gatame or a juji gatame on someone, they not gettin'out o' that hold.If they do, something went horribly wrong.
But in trining, we let 'em get out to practice follow up after follow up hld, and let them get us in the hold to practice escapes agaisnt those whoare less than perfect in their execution.
I didn't see what you saw, but of course I have seen syles less effective than others, or practitioners that seem less effective than others.
I have also observed dilletantes who jump on this or that bandwagon.But when someone real grabs you, by Gum, there is no mistake. If they want you in one hold, youstay there. If they want to tansition you, transitio you they will.
But there are of course those who say they know jujitsu, and took some lessons or got them some tapes, and when you get out n the mat with them, well, hey! That's some fun, hah, guys?

Had a guy once come into the dojo, from an Aikido/JKD Club taught by Lord knows whom.
I demo'ed an irimi nage slowly, and he got up and said, when I asked if it felt real, 'Not realenugh for me! ' And came charging straight in to me with a punch!::-)
Clotheslined him straight out in the air and he hit with a thud.'That real enough?'
'choke.'"Uh-yeah.'
Good, I said cheerfully. Then we don't have to do it more than half speed.

'
First open the wound, Then rub the salt in , I always say.:-)
Kusanku