I tested this repeatedly on my test website,
www.jtest.us. On this site I installed Kunena, Jomsocial, JFBConnect with all plugins, did not enable the Content plugin. Then I ran a bunch of tested learning how the modules and plugins live symbiotically. On the site home page I made up a content article and at first set up all three plugins, Like, Comments and Share. Only Share would display. If I disabled Share the other two worked fine.
Yet I also found that if I enabled Share I lost the FaceBook image and login function in the left column. If I went to the Jomsocial home page where the content item with Share was not included the Facebook login worked fine.
Is this the way it is supposed to work?