You referred to them as "easy leg break techniques." If they were easy to do then why would LeBell even bring it up in the interview? The remarkable thing is that it's not easy to do, yet Karl Gotch accomplished it consistently. That's how good he was. That was what made it worthy for inclusion in the interview Joe Rogan conducted with LaBell. I hope that clears up the mystery for you.
Why didn't I engage your other points? Did you really expect me to "engage" the following: "I really doubt the few Americans trained in JJ guys even attempting the guard much." Alright, you doubt it. So what?
How about this gem: "Whose legs did he break"? Gotch broke the legs of any of the jiu-jitsu guys who challenged him and used the guard. I didn't "engage" that point of yours because it was already explained.
If you're so interested in finding out more about it why don't you listen to the interview with Gene LeBell that Joe Rogan conducted in which Karl Gotch was discussed?