When the Dark Zephyr finally flew all the way back to Fort Fishblood, the rich amount of scouting data and personal notations provided by Venerable Tusa ignited a bomb among the expeditionary forces!
"There are more groups of fish-whales in this pocket space!"
"Are the four 'kingdoms' hostile towards each other?"
"The Swarm Kingdom is much larger and stronger than the other three fish kingdoms. I bet that it has probably overrun a few other groups throughout the history of this pocket space!"
"How can we do anything in Purgatory with all of these scary fish-whales in place? Even if we conquer an asteroid at great cost, the other fish-whales can easily swoop in and push us away!"
The existence of multiple fish kingdoms, each of which were presumably hostile against each other as well as outside intruders, massively complicated the strategic considerations of the human invaders.