In my story, there is a war between humans and a slightly more advanced and clever species. The humans outnumber the other species and end up winning the war because the humans spread a virus to the species that wipes out even more of its population. The humans are the only ones that could develop a vaccine for the virus.
Humans and this species are very similar, but members of that species are larger, stronger, and more quick-thinking than humans. Individually, an educated member of that species could outsmart an equally educated human.
Humans have a slight advantage because they can reproduce faster and require a bit less resources than the other species. After winning the war, the humans are able to reverse engineer a lot of the tech from the other species.
Would humans be able to enslave a cleverer creature? How could they control this species enough to enslave its members? Would going through the trouble to enslave the species be economically worth it?