W/out the success of Michael Jackson, there wouldn't be a Jackson 5 that 99% of the world has heard of. Berry Gordy has credited Michael as standing apart as a prodigy/outstanding talent in To Be Loved, his autobiography, and in recent interviews. Even the most casual music fan knows that Michael sang lead on all of their hits; further, young Michael also had solo hits and appeared solo on the cover of Rolling Stone in 1973.
Michael's first albums succeeded: "Got to Be There" hit number 14, hardly a "failure" for a debut artist (going by the theory of the J5 never existing), and the follow-up "Ben" hit number five. Both produced a total of four top ten singles, three of which hit number one on one of three major US charts:
http://en.wikipedia.org/wiki/Michael_Jackson_singles_discography. Ben also won a Golden Globe, and was also nominated for Best Song at the Academy Awards:
http://en.wikipedia.org/wiki/Ben_(album).
Whether judging by Michael's solo albums or Jackson 5 career, he was an instant success. Janet wasn't. This post is not an "attack" on Janet -- she's done very well for herself -- but I don't see the point in fabricating statistics or discrediting talent or Motown's founder.