"Would this, university, still be running now? The empire that has annexed your city will now have access to all that information, and even if they already knew about things like farming and such they will still benefit from the other knowledge that you mentioned. They could also use your city's ties to all the tribes that have made these interactions with your people to cause them to join their empire without any of them knowing what actually happened to your city." Onyx didn't like to think about how much smarter their enemy most likely was than her people, and she couldn't stand the fact that Tarentek didn't seem to be worried about it much. 

"Which scenario would be worse," She started, "If everyone were to join them willingly and never be themselves again, or if we all died fighting them and possibly stopping the spread of them? I can tell you now that all the tribes of my race, whether friend or foe, will not give their freedom up to this empire."