Which workflow to choose for modifying external git repositories?

Question

git

We have a git repository in Python. It imports a few other modules (not ours, but available on Github) that need a few changes. The question arose about how to organize this in the best way:

Option 1. Fork external repositories, make changes to them. For your project, create a virtual environment in which to install the forked repositories.

Option 2: Fork external repositories, add them to the project via submodules (or even subtrees ).

Option 3. Just copy other people's repositories into your project (fortunately, the license allows).

Of the features:
- changes to external repositories will be made quite rarely
- the team is not programmers, but engineers, among which many are from git to "you" (that is, non-trivial git errors can paralyze work).

Apparently, this cuts off the second option. The third option does not allow you to update external modules. Everything seems to be fine with the first one, but if external modules are updated, both the forked repositories and the virtual environment will need to be updated.

Actually, the question is: is this approach correct? And how is the issue with the modification of external modules usually solved?