Other than freeing up memory where the binary would be loaded and maybe some network ports I don't see any advantage to scaling two "light weight" services separately.
I see your point. Having services entails more complexity.
That said it allows you to tailor your code to its specific need. One of the services needs a certain database, or queuing or other connectivity considerations while the other doesn't or has different needs. Having them bundled prevents you from splitting things out. You don't have a limited and specific design.
