Hippos don’t belong in South America. They have no natural enemies so they’ll breed like rabbits. Yes,I think that they should either be killed or moved to Africa. Of course moving them to Africa would be damn expensive...so death is the only reasonable plan.
While it’s apples and oranges, we have a feral pig problem. Same thing, they breed like crazy. Least Hippos stay close to water, pigs go everywhere, bulldozing along away.
Florida would be closer and cheaper. After all, Florida seems to be the dumping ground for all the other invasive species other than the rare snow spider.