Yeah, that's basically it.
The War Kai are big, aggressive, tough, and hungry, if not outright cannibals. While they are not dumb, they are basically interested in "Kill everything not 100% us, eat everything, and remake the Galaxy in our image." The concept of "peace" and "surrender" simply do not exist for the War Kai. Almost pure brute force - War Kai would absolutely spam reinforced missile bombardments with adapted Kai and Flowers and perform suicide drops.
The Body Kai were the real horrors, though. They were the "evolution" Caste. Comparisons to Nazi medical science would make the Nazis look kind, gentle, and reasonable. BodyKai were the really big slavers, and were especially fond of unleashing plagues and making Kai form versions of the other species. The War Kai did not like them because of the blasphemy of imitating lesser species, but did not go after the Body Kai because of the threats of Flowers that could (and did) infest the Kai and basically utterly eliminate the War Kai through the sterilization of the Flowers.
Also, it's not that they cannot adapt well. It's more that there is a secret group headed by the True Queen that possesses the ability to do so, and mostly dictates how adaption goes. Lesser Kai can certainly adapt and play within their limits with a large amount of relative freedom, but it's more like being given enough rope to hang yourself. The Queen is too tricky to leave herself exposed to the same thing that she pulled.
(Also, the quiet implications are that the True Queen possesses a very large gene library, and is taking the time to slowly and selectively breed and experiment.)
I can say that yes, you can ask to keep some, and the Queen would consider allowing you to retain certain parts and hand over a reasonable shipment of Royal Jelly and a few trusted Minders to be sure you're not trying to pull off a coup and are sincerely working for the species. Trying to just plain keep it will definitely make some enemies among the Kai, and the Queen can certainly say "The Merops were deliberately creating Slave Kai to help them in thir plans for galactic domination and these rebels stole it instead of destroying it! Here's all of the data we have, we're paying for leads, and they are wanted dead for a giant reward."
Not everyone will accept the argument, but she will certainly paint a giant target on you and spend considerable effort on hitting you first.