Contemporary armed groups often defy traditional legal categories. Many operate simultaneously as political insurgents, transnational criminal networks, and parties to armed conflict. Their hybrid nature challenges the coherence of criminal procedure and international cooperation frameworks, which continue to rely on mutually isolated and procedurally compartmentalised legal designations: terrorist organisation, transnational criminal group, or armed actor under international humanitarian law. These labels are not merely descriptive: they activate distinct procedural regimes, determine available cooperation mechanisms, and shape evidentiary standards. This paper examines how divergent legal designations, by activating different legal regimes, influence cooperation and procedural fairness across jurisdictions. It primarily draws on three case studies: France’s counterterrorism prosecutions of returnees from Syria, Germany’s universal jurisdiction trials under the German Code of Crimes against International Law (Völkerstrafgesetzbuch, VStGB), and the ICC’s Al Hassan case. This paper argues that the interplay between counterter-rorism frameworks, organised crime cooperation tools, and international criminal law produces competing evidentiary thresholds and fragmented chains of custody, especially when intelligence-derived material enters criminal proceedings. When hybrid armed groups activate several legal regimes concurrently, differences in procedural and cooperation frameworks can give rise to challenges relating to equality of arms, legality, and reciprocity in judicial cooperation. The paper suggests that addressing these challenges may benefit from procedural adaptations that improve coordination between existing cooperation mechanisms while preserving established due process safeguards.