In L2SecurityCouncilMgmtFactory.sol, the deploy() function only checks that every address in every cohort is an owner in govChainEmergencySCSafe:
L2SecurityCouncilMgmtFactory.sol#L111-L121
However, there is no check to ensure that firstCohort and secondCohort do not contain any duplicates, or that any address in one cohort is not in the other. This makes it possible for the SecurityCouncilManager contract to be deployed with incorrect cohorts.
Consider checking the following:
