Do you have a Time Machine backup containing these same files in an undamaged state? If so, a restore of the individual files can save the day.
Pages (or Numbers) is very particular about the integrity of documents it is asked to open. Once it complains about the document, such as invalid file format, then you are likely done. You can boot into safe boot mode, and try opening these documents, followed by a normal reboot, but I doubt it will resolve the issue.
If you used any file recovery software to retrieve those files from that faulty WD drive, then that recovery software could not possibly have reconstructed the Pages (or Numbers) documents' internal content correctly, as only Pages (or Numbers) can do that. That would also explain why those RTF files cannot be opened as it sounds like they are damaged too, but for a different reason. In the latter case, can TextEdit, or even LibreOffice v7.2.5 (current) open those RTF files? LO won't handle any RTFD files though.
If Pages documents were double-clicked on Google Drive, or on Windows, the default action is to unzip (and irreparably damage them).
