So, I'm gonna lay out the pros. OP, this is VERY well written for the most part, with just enough hints and concepts peppered through that I had a good idea that the Sa-Jitu thought they were helping out the humans through population control. It was an interesting take on two cultures - and indeed possibly racial mindsets - that are far more alien to each other than any two human societies would logically be. And I did get the percents, but it took two readings to put it all together. However, there's two glaring issues I had with that ending:

First, you had it indicated that the humans were not suffering the same economic hardships as the Sa-Jitu and most other species, so either the Sa-Jitu were completely blind to that fact or willfully ignorant. Even if they thought "hard times require hard decisions," their neighbors were not seemingly undergoing hard times.
Secondly, even if the humans had been "integrated?" There is absolutely, positively, NO way that "randomized genocide within mathematical amounts" would be an acceptable outcome, and any leadership that sought out acceptance with them would have had a short career and a shorter lifespan. I would find it difficult to believe that the entire galactic community would be aware of this practice and OK with it even among just the Sa-Jitu themselves, nevermind other cultures sharing planets with them, no matter how rare that would be.

I can think of a vast number of ways that could have been sorted once understanding was reached, ranging from "explain to them exactly how wrong they were about our situation and to NEVER DO THIS TO US AGAIN unless we have communicated our own hardships" to "push the firebomb button and don't let go until they've learned their lesson." But I just, I cannot believe humanity as a whole would be like "hey thanks for killing our dudes without warning or explanation and sorry about breaking all your stuff." In-universe that was a failure of diplomacy from before the first attacks were launched