Majority vote is a very simple system to reason about. What you’re describing adds a whole bunch more complexity. For the noise sensor scenario, is the sensor

Majority vote is a very simple system to reason about. What you’re describing adds a whole bunch more complexity. For the noise sensor scenario, is the sensor failing or is the ancillary (and single point of failure) noise sensor failing? What happens when you have a false positive like that and a false negative on another sensor? For the correlation scenario, when you have two systems that disagree, how do you determine which one is failing? Are their precisions and tolerances sufficiently close that you’ll get a warning at a useful point in time?