The instances should be based on the context. For example we had a few different API providers for the same thing, and someone refactored the separate classes into a single one that treats all of the APIs the same.

Well, turns out that 3 of the APIs changed the way they return the data, so instead of separating the logic, someone kept adding a bunch of if statements into a single function in order to avoid repeating the code in multiple places. It was a nightmare to maintain and I ended up completely refactoring it, and even tho some of the code was repeated, it was much easier to maintain and accommodate to the API changes.