The planetary management system had over 1000 sub-systems to help maintain control over the 13 authorities.
The 13 authorities also had their own systems that managed the entire planet.
It was better to say that the systems were managed by these authorities because the 13 individuals had the power to veto the decision of the planetary management system in normal situations.
The Overlord was the topmost authority and he managed the whole planetary management system. While his title may sound overly tyrannical, he/she had very little room to force the other 12 into a decision.
The overlord managed the whole system and would not interfere with others during normal times. This was to ensure that the other branches developed independently and it also ensured that the overlord did not have too much power.
Such power would be toxic in a well-developed civilization. Too much power during peace times is as dangerous as too little power during war times.