Local variation and divided command also serve as safeguards against rebellion. During the Horus Heresy, forces away on crusade split broadly between loyalists and rebels, while most formations retained on defensive duties remained loyal. Breaking the later Navy into five segmenta and still smaller commands reduces the chance that one defection will carry an entire service with it. The arrangement trades some unity for institutional resilience against another empire-wide military seizure of power.
Notable Point · 22:03-25:32
Distributed fleets limit the scale of rebellion
Dividing naval power among segmenta and lower formations makes it harder for corruption or rebellion to capture the entire Imperial fleet at once.