General CAD design/assembly question
Once you get used to using any CAD program, you develop your own preferred workflow. I know some who prefer making individual drawings and then putting them together as an assembly afterward but also know others who do all assembly parts in one drawing.
I personally prefer working with individual files for all the parts (cleaner that way). It’s good to pay attention to universal coordinates when doing this though, i.e. make sure all your files have a common reference origin point, since that makes it much easier to insert all the pieces together in one assembly file at the end of the process.