What about joining page 2-3 from PDF A with page 7-23 from PDF B? I remember that being a huge hassle on macOS when I was using it years ago. Think I ended up using some cloud service/website for it since the documents weren't confidential at all.
The only downside to this, that I am aware of, is that a new PDF is created (rendered into a new PDF context). That can be lossy in some cases (if there are features that Preview does not support that get "dropped on the floor") and it is possible for the resulting PDF to be larger than the original(s).
pdfjam [1] uses a LaTeX package under the hood, is included with the TeX Live distribution and acts as a wrapper for a LaTeX package. With this, I believe your example would be: