Let us presume that everything goes right for Justinian in his reconquest of the West. Italy falls as easily as Africa (and the Lombard looks elsewhere), and Hispania soon after. Gaul falls with more effort, maybe takes a generation, but is conquered as well.
How does history look on this period between the end of western emperors and the reconquest by Justinian? Similar to the Crisis of the Third Century? Might the histories attribute some credit to the Catholic Church as a unifying force?