[@Raptorman]
It's not.

It's because the Consortium's Composers aren't really as all-knowing as they think even with their bio-mechanical doppelganger spies and make bad assumptions about other societies.  The horde is comparatively distant, so not too much is actually known on how the horde works.  They just assume it to be like the Empire but much more savage without even being aware that their leaders come from taking the position through bloodshed and not heredity.  Even if they learn how the horde actually works, they'd still propagate the blatant lie that the horde is nepotistic to make them look no better than the Empire.  The Composers tend to hold actual power despite the Auditor being autocrat since the Composers dispose of Auditors who they find ill suited for the role.  (Read: Call them out on their bullshit or try to weaken their position in the Consortium)