The major difference is whether the small projects are independent applications that use some shared libraries (what I think you mean by "existing generalized components") or whether the small projects all talk to each other to create a single large application.
If it's the former then you're just talking about refactoring functionality into a shared library, but at the end of the day you're still just building little monoliths. You don't have to worry about most of the problems that come up with microservices.
If it's the former then you're just talking about refactoring functionality into a shared library, but at the end of the day you're still just building little monoliths. You don't have to worry about most of the problems that come up with microservices.