I have had experience messing with disease models before, whether it was playing with the off-brand Plague Inc. knockoff Pandemic 3 or designing a model of a more scientific nature.
I learned that Plague Inc was just as faulty as it was fun. It didn’t calculate things it should have. For example, a disease could spread throughout the world implying the entire human population could be infected with a disease at the same time for an indefinite amount of time, without accounting for recovery or natural immunity. Not all conditions related to certain countries were taken into calculation either, such as climate, population density, and sanitation, and it was a challenge to figure out which were and weren’t.