Wow thats almost exactly what my jujitsu school has taught me about the history of jujitsu and karate. That really jujitsu is all self defense, with karate being part of it, that the modern day jujitsu is just throws and grappling, but the original jujitsu has all the karate strikes and katas as well.
This is sort of what I posted on E-budo yesterday, commenting on the decay of the martial arts and the very existance of "cross training." In feudal Japan the samurai clans taught the martial arts as a whole, not cut up into pieces like we see today. Jujitsu was striking, aiki jutsu and nage waza all in one systematic whole.
I don't know about the historical points of the beginnings of Judo, but the rest of the article is in agreement with what my instructor has taught me. Great write up.