After Larry Barese backs out of Richie's idea to whack Tony, why didn't Junior have someone go and assure Larry that Richie had his support? Or better yet, let Richie kill Tony, then have Richie whacked and re-establish control using one of his supporters (for example Patsy Parisi) as Acting Boss?
Junior answers your question. He says Richie couldn't sell it, he's not respected he flat out says he's better off with Tony. I remember that scene well because of Bobbys hilarious respone to the question what are you looking at? ''i'm in awe of you''