I mean… if you have unlimited resources and unlimited speed, going multiprocess makes complete sense.
You can write this in async with a pool of connections to each provider, or you can have a pool of worker processes that each have one connection to each provider.
Which will be easier to debug, and which design is easier for the next developer to read, understand and modify? Performance wise the wast majority for both designs will be on waiting at the initial connections to the apis and time spent fetching objects.
It would be interesting to hear what kind of domain are you working in where you have 3000 simulations connections to different service providers.