Symbiosis as a systemic catalyst and the impossibility of coalitions in optimal networks

The stability of complex systems hinges on the tension between individual incentives and collective welfare. Modeling these dynamics through strategic network interactions based on anti-coordination, we formally prove that any globally optimal configuration constitutes a Strong Nash Equilibrium, creating topological barriers against collective deviations. However, in sub-optimal states, strictly individualistic agents remain trapped in stagnant equilibria. We show that coalition formation acts as a vital catalyst for global efficiency. Paralleling Tomasello's evolutionary theory of shared intentionality, the emergence of symbiotic joint agency overcomes selfish stagnation and drives the system toward optimal niche partitioning. We validate our framework through extensive computational simulations and apply it to an empirical pollination network, demonstrating how symbiosis may steer real-world ecosystems toward maximum resilience. We uncover metastable dynamics where coalitions continuously reconfigure, revealing that biological evolution relies on a perpetual, adaptive balance between competition and cooperation.