The Bible Student groups still in existance claim that C. T. Russell was not the founder of the JW religion. In fact if one examines today's Bible Student doctrinal structure it is basically the religion that Russell taught. So the JWs are actually a break away from Russellism. Just like Russell's religion was a break away from Second Adventism.
What makes it confusing is that Rutherford won control of Russell's printing corporation, the Watchtower. Then Rutherford dumped many of the Russellite doctrines and replaced them with his own, creating a new religion. This resulted in over 75% of the original Bible Students leaving the Watchtower to reorganize independently and restore Russell's religion in their congregations.