The hive as a whole are brainless and erratic, much like the taken where sometimes a character like oryx exists to do something meaningful. The eliksni barely managed to expand outside their own solar system before getting curb stomped, but the cabal had a galactic empire with several subjugated races. Even now their military might is staggering with how fast they mobilize, they also managed to invade the dreadnought and find tech to silence the light before advancing that tech to use during the red war without being paracausal. Best the eliksni did was alter their bodies with siva and not siva before immediately failing to do anything with it. The origin story of the hive is them being duped into being servants.