Does anyone know who owns the Facebook page in the OP? It may not be owned by the SSPX. Maybe it's a layman who has a grudge against the Resistance.
The Resistance under Bp. Williamson is unified. The four Resistance bishops, and the priests who are affiliated with them get along quite well, from what I can tell. They don't associate with Fr. Pfeiffer's group, that's true.
By the same token, one could say that the priestly fraternities whom provide the traditional sacraments are splintered. After all, the SSPX is not unified with the FSSP or ICK. Though they might like to be. When the Archbishop was alive, after the consecrations, he said that those who left the SSPX at that time to reconcile with Modernist Rome (who became the FSSP) were traitors. I don't recall him saying that unity among traditionalists was his biggest concern. He wanted to keep the traditional sacraments alive.