Fic idea: Everything's a predator!
I swear this isn't just Whoopsies all predators
For this one, everything goes like normal for history, until the Farsul and Kolshian come across the Krakotl. Instead of opportunistic piscovores, the Krakotl are obligate carnivores that make fish half of their diet and can't be cured otherwise they'll die
Now, would the Federation come to its senses and reconsider it's stances on meat eating and predators? Of course not!
But what to do about the Krakotl? Well that's easy! Gently teach teach them at gun point how red meat is vile and predators are evil. Problem solved until they can figure out how to genetically modify the Krakotl into being herbivores
Except, every species the Federation comes across are obligate carnivores. Worse, they all have predatory traits that the Federation can't explain away. So to put a temporary solution on the problem, they push them into becoming piscovores and convince each species that predators are evil, except those that eat fish because fish are lesser creatures so it doesn't count, and that predator disease comes from eating meat that doesn't come from fish, while also convincing them that other predators still want to eat them
So the Federation has a bizarre hybrid of its canon ideology that teaches that piscovores are just fancy prey, while desperately trying to figure out how to cure everyone without starving them to death
Then of course the Federation comes across the Arxur, and they'll die if they only eat fish, but Betterment has to convince them that piscovores aren't actually predators so don't count as sapient, so it's ok to eat them, while in the background both Betterment and the Shadow Caste are trying to find a way to make everyone into herbivores