Assuming that the issue of fragmentation of international human rights law can also be usefully examined in the case-law on particular rights using a comparative method, this article examines the divergence and convergence of freedom of assembly guarantees and jurisprudence in international fora. It finds that some identified divergences in fact point to underlying common concerns and assumptions about assemblies. On this basis, the article argues that the fragmentation discourse is prone to structurally analogous, though “reverse”, fallacies as the methodology of comparative law. In particular, the functionalist method is much criticised for being apologetic or trapped within one's own conceptual and institutional system, a concern which might be present in the fragmentation debate as well. The article concludes on this basis by formulating some suggestions which might be applied to examining fragmentation in international human rights law and potentially beyond.