This paper extends the capillary navigation engine of DeMase (2026a–d) to multi-agent cluster settings under bounded attention-energy budgets. Multiple high-Γ proposers are jointly verified by a low-Γ pilot maintaining a coherent portfolio of admissible branches. The principal new result (Lemma 4ᶜ) establishes a computable lower bound on stealth portfolio maneuverability collapse under structural doubt. Any coordinated adversary reducing maneuverability from M₀ to M₁ while remaining below the joint threat threshold requires at least k* = ⌈(M₀ − M₁)·δ_res / (N·‖B‖_op·M_adv·B_max)⌉ steps. This yields a proactive rate-based detection statistic (COMMITMENT_ALARM) and formally bounds the Commitment Adversary class for the first time in the series. The extended lexicographic graft rule is proved unique within the admissible cluster class. Simulations verify the non-vacuous detection regime and illustrate correlated geometry collapse as a higher-order attack surface.