I have played in a game where VIPER made a lot of the villains. They also only got one super out of 100-1,000 'tests' the rest... missing person.
We got a tape of a nest leader saying 'So, Five Supers with only 2,500 dead from treatment Xz-123-a16-alpha. So, the answer is, yes, we can create Super at will. The next 'test' better work better. How is Xz-123-b3 coming along? You need to boost the power levels of our new Supers and get the cost down. If you can't cut the dose cost then work on cutting the death rate, and see if you can cut the rogue rate to. I hate to see us lose a Super that we made."