before the westerners shown up in Japan, Japanese tent to have the similar build. when westerner shown up, i believed various Asian martial arts made changes to accommodate the different builds. I was watching the show on the life of Bruce Lee on TV last night. They shown the scene in the Game of Death where Bruce fought against Kareem Abdul Jabbar. I was thinking if someone with the build of Bruce doing ikkyo on someone like Kareem, exactly the way O Sensei shown, that wouldn't work very well. For one thing, Kareem would just pick up his arm and toss that person across the room like a basketball or pick up his arm and let you dangle, running in mid-air.
To me, techniques are just manifestations of principles, and which one you apply is determined by what is being presented to you at any given moment. When being attacked by a giant, the last thing I would want to do is extend him up - it would be more like bring him down with a nice atemi shot to his knee; which of course would be at my eyeball height