I disagree. Pam was the focal point of the Barnes Ewing feud. She was the only link that connected the two families. Which is why when the Pam character was gone, Cliff was just floundering around without any purpose except becoming besties with Bobby. There wasn't a feud anymore.In addition following the sad death of Jock, JR was the focal point of the Barnes Ewing feud. You can then appreciate why JR became the breakout character on Dallas because of the Barnes Ewing feud.
JR and Cliff were the antagonists of the feud and Bobby and Pam were the protagonists caught in the middle. The only time Sue Ellen became part of the theme of the show was the brief time she was sleeping with Cliff and possibly carrying a Barnes heir instead of a Ewing.