Correct approach for dependencies with npm when dealing with submodules

Question

i have some questions and regarding the proper way to handle dependencies in nested projects, added via git submodules. lets assume this structure:

further assume in the top-level package.json dependencies need a react version > 16.7. In the submodule a strict version of 16.3.2 is needed.

when i now run npm install on the top-level, does npm install multiple versions of react? (don't see something like this in node_modules) but it seems to install modules declared only in submodules package.json. (how are they even found at compile time?)

There are certain warnings in the console however, that there might be multiple versions of react running... What would be the best practice to handle such a situation? Thanks in advance