When Germanic and Gaulish (read as Gallo-Romance) people convert to Christian, they already made a different branch of Christian. The mass majority of Western Europe Christian had no presentation in Ecumenical council, their religion evolved in a completely distinct part from the rest. Charlemagne made great effort to re-introduce Latin and Greek tradition, it would be a big irony if such effort is now interpreted as an act to create a new branch of Christian.